Geology misconceptions targeted by an overlapping consensus of US national standards and frameworks

ABSTRACT

In the past few decades, scientific and educational entities in the United States have repeatedly expended considerable fiscal and human resources in an effort to establish contemporary education standards, curriculum frameworks, and assessment tools. These efforts are intended to reform the quantity and quality of K-16 Earth science education across the U.S. including, most recently, the Next Generation Science Standards. Most of the reform efforts enthusiastically recommend a constructivist-oriented approach to instruction that requires educators to clearly identify their learning targets. At the same time, a contemporary approach to instruction requires educators to be aware of misconceptions, misunderstandings, naïve beliefs, and alternative frameworks students bring to the learning experience. Although several dated surveys of learners’ geology misconceptions exist across the scholarly literature landscape, little of the geology misconceptions literature is systematically organised around the current collections of U.S. national standards and frameworks. Geoscience educators, curriculum developers, and assessment specialists benefit from summaries of misconceptions research organised around various national reform efforts.

KEYWORDS:

• Geoscience education
• misconceptions
• standards

Contemporary global challenges have renewed widespread interest in enhancing geoscience teaching and learning across the globe. At the same time, many international curricular frameworks for the teaching of science – including those across the U.S. – are embracing a constructivist-oriented model of teaching and learning. As a result, geoscience educators are enthusiastically seeking applicable data on misconceptions that students bring to the classroom. Part of what drives educators’ longstanding interest in students’ misconceptions is the now decades-old philosophical perspective advocated by Ausubel, Novak, and Hanesian (1968) that the best teachers assess what students already know, and then teach them accordingly. This perspective serves as a foundation for constructivist-approaches to teaching (Saunders, 1992).

Indeed, there exists a long and somewhat fragmented history in geoscience education of cataloging and publishing students’ misconceptions across the geosciences. According to GoogleScholar, the most highly cited article about students’ misconceptions in Earth science is that of Philips (1991). His paper was not a report of a formal research study, per say, but instead a listing of students’ misconceptions encountered by long serving Earth science teachers. In service to those geoscience educators who wanted to know the most common geoscience misconceptions, Philips (1991) lists over 50 misconceptions in bullet list form. Unfortunately for discipline-based geoscience education researchers, he provides no indication of which our diverse students hold these misconceptions, or their relative frequency.

Most recently Mills, Tomas, and Lewthwaite (2016) published a peer-reviewed, systematic review of literature on conceptual change instructional approaches in the Earth and space sciences. Rather than cataloguing students’ misconceptions, the authors identified effective instructional approaches that target students’ misconceptions. Although the authors identified 52 studies, only a few focused on the Earth sciences. Because of this the authors noted that more research was needed in this area.

The most widely cited, peer-reviewed paper about students’ geoscience misconceptions is that of Dove (1998), although far less cited than the informal reporting of Philips (1991). Using a traditional approach to conduct a literature review, Dove (1998) reported on the literature she could find as of 1998. Far more comprehensive than Philips (1991), Dove (1998) listed 35 misconceptions and attributed their identification to individual authors. While this systematic review was more ‘scholarly’ than Philips (1991), it was limited because few systematic research studies had been done prior to that publication date.

The most comprehensive literature review published as a peer-reviewed article in this Century appears to be that of Francek (2013). Francek collected and organised 500, an astounding number, of students’ geoscience misconceptions. Unlike the Philips (1991) or Dove (1998) review, he treated the traditionally scholarly literature and grey literature equivalently. Grey literature is commonly defined as the domain of research and teaching reports disseminated through non-referred conference proceedings, professional presentations, and education newsletter-like publications. There currently exists disagreement in the geoscience education community about the value of non-referred grey literature (Slater, 2016). On one hand, it is perhaps his inclusion of non-refereed grey literature that results in far fewer citations of Francek’s larger published literature review than those much smaller reviews by earlier scholars. On the other hand, it may be that Francek’s review fails to be efficiently organised in a manner immediately useful to contemporary discipline-based Earth science education researchers or curriculum developers. In either case, his laboriously, extensive work seems to have had little to no obvious influence on the most recent manifestations of U.S. national curriculum standards or frameworks efforts, either by inspection or by citation.

Adams and Slater (2000) published what turned out to be a highly influential and highly cited review of astronomy misconceptions. They aligned their misconception categories with that of the U.S. National Science Education Standards (1996). In doing so, they were able to identify obvious gaps in the literature landscape that motivated a number of published research studies in the following decades (Bailey & Lombardi, 2015). Given the success of this approach in astronomy, one wonders if a new review organised around a consensus of U.S. national educational standards for geology education that also focused on clearly identifying the research-based establishment of such misconceptions might also serve as a watershed event to guide the scholarly agenda of the next generation of geology education researchers. The overarching question driving this literature review is which student misconceptions about geology concepts exist in the scholarly literature base that are poised to interfere with the implementation of elementary and secondary level geology curriculum standards and frameworks in the U.S?

Method

Organising structure

In an effort to identify which geology notions are poised to interfere with the successful teaching of concepts modern curriculum standards and frameworks, we first identified the guiding curriculum framework that would serve as our conceptual organiser. This is the first step in the standard literature methodology used by Adams and Slater (2000), which we followed as a model in this work. As one might naturally expect in the U.S., we used the 2013 Next Generation Science Standards (Achieve, Inc., 2013), hereafter abbreviated as the NGSS, as our initial organising structure.

We then expanded our organisational structure because in recent decades in the U.S. and elsewhere, geoscience educators have devoted considerable effort to creating consensus standards and frameworks to guide geology education. Instead of ending up with a single geoscience education reform document, competing efforts have now resulted in numerous geology education standards for teachers in the US: NSES (National Research Council, 1996); Benchmarcks for Scientific Literacy (American Association for the Advancement of Science [AAAS], 1993); Earth Science Literacy Principles (2010); NGSS (2013) (Guffey, Slater, Schleigh, Slater, & Heyer, 2016; viz., Slater & Slater, 2015). As a result, instead of selecting just one of these competing frameworks to organise a contemporary review of students’ misconceptions in geology, as a secondary position, we judged it would be most fruitful to create a review of misconceptions around a consensus of the U.S.’s community’s overlapping ideas about which concepts should be taught in geology.

A consensus of the 11 core geology concepts was created by determining the overlap of national education reform documents (AAAS, 1993; NGSS, 2013; NSES, 1996). Next, we surveyed the scientific accuracy of the established categories by surveying geologists and geology educators on their content and revised based on their expert feedback. The end product was a consensus document which provides the overlapping 11 core ideas suggested by a consensus of national reform standards documents and from the content experts (e.g. geologists). An extended discussion of the specificity of the overlap was determined is described in detail elsewhere (Guffey & Slater, 2020). Adopting such a more inclusive posture allows our contemporary review of common student misconceptions to be efficiently applied to students being taught under NGSS and other students as well.

Procedure

In order to generate our modern, comprehensive review of student misconceptions surrounding geology concepts important in a consensus of curriculum frameworks and standards, we conducted a traditional, systematic review of the literature. This type of review has most commonly been associated with the medical field (Murlow, 1994) and is relatively new in the field of education as a result of ‘changes in policy towards evidence-based practice: benchmarking and performance indicators are being used to encourage teachers and educational developers to achieve given targets set from national baseline standards’ (Perry & Hammond, 2002). The method often involves a team of researchers to minimise bias and uses a set search strategy with many predefined databases (Perry & Hammond, 2002). As a departure point, we searched for the terms ‘geology misconceptions’ in GoogleScholar and ERIC (via Ebscohost) in which both resulted in an extensive list of publications, including the most commonly referenced literature reviews in geology misconceptions from Dove (1998) and Francek (2013). We then used the cited-forward functionality of GoogleScholar to determine which papers since those initial publications cited Dove (1998), Francek (2013) and the extensive references therein. This generated a list of more than 330 publications to review.

Our final step related to searching was to use GoogleScholar, ERIC, and ResearchGate and the abstract databases of the Geological Society of America, the National Science Teachers Association, and the National Association for Research in Science Teaching to specifically search for papers related to the previously uncited misconceptions related to geology-concepts from Philips (1991), AAAS (n.d.) and MiTEP (2010).

The inclusion criteria for the papers were straightforward. First, the concepts needed to be directly related to overlapping consensus concepts. Second, we prioritised peer-reviewed published journal articles over the grey literature of unpublished dissertations and conference presentations, and only invoked that later when there was no other option. We did not require that the studies be done on U.S. students because if one were to constrain the research reviewed to only U.S. authors and students, this review would be wholly incomplete and that extending our reach to include the highly valuable work of international researchers provides the community with a more complete view of the scholarly landscape. This resulted in reviewing a total of 66 peer-reviewed published journal articles that met our criteria.

Results

The following systematic review of the misconceptions in geology literature, summarised in Table 1, is organised around the 11 overlapping ideas originating in the four dominant education reform documents in the U.S.: AAAS, NSES, ESLP, and NGSS (we leave expanding this portfolio to international documents for a future study). Where possible, the same wording and phrases were used from the original documents. The sequence of the topics is arbitrary.

Table 1. Summary of misconceptions research.

Consensus Learning Target	Misconceptions Research to Date
1. Earth’s crust is broken into plates, which slowly move in relationship to each other, driven by convection currents in the mantle.	Clark and Libarkin (2011) found students confuse spreading ridges with hot spot and are unable to identify directional motion of boundaries without arrows. Melting occurs at great depths due to high temperatures rather than changes in pressure or chemistry. Sibley (2005) finds students do not conceptualise crustal thickening at continent-continent margins. King (2000) and others find students overestimate thickness of crust.
2. Atoms of different elements combine to make minerals, which combine to make rocks. Rocks and minerals are classified by on their chemical and physical properties	Happs (1982) and others report students use superficial characteristics when classifying rocks and minerals. Rule (2005) reports students lack sufficient conceptual framework to predict location of fossil fuels.
3. Earth materials take many different forms as they cycle through the geosphere. Rocks form from the cooling of magma, the accumulation and consolidation of sediments, and the alteration of older rocks by heat, pressure, and fluids. These three processes form igneous, sedimentary, and metamorphic rocks.	Kusnick (2002) found students have little conception of porosity among solid objects. Stofflett (1993) finds students attribute weather conditions to all rock formation processes. Students conceive of rock cycle for categorisation rather than formation processes.
4. Earth’s rocks allow us to reconstruct Earth’s history, giving both relative and absolute dates	Libarkin, Anderson, Science, Beilfuss, and Boone (2005b) reports students do not know age of Earth. Trend (2000) finds students underestimate timescale lengths and believe life and Earth’s formation were simultaneous. Prather (2005) report students conceptualise half-life radioactivity as being equivalent to disintegration.
5. Fossils provide evidence about the types of organisms that lived long ago and the nature of the environments at the time.	Petcovic and Ruhf (2008) found students only conceive of fossils as remains of living things. Schoon (1992) and Schoon and Boone (1998) find students often think that dinosaurs and humans coexisted. Dodick and Orion (2003) report students think older fossils are always less complex than more recent fossils.
6. Earthquakes, mountain building, volcanic activity, and ocean floor features occur at plate boundaries as the result of plate movement.	Barrow and Haskins (1996) and Parham et al. (2010) report earthquakes and volcanoes most likely to happen at continental coastlines and in warm equatorial regions. Libarkin et al. (2005b) found students rarely connect volcanoes and earthquakes to plate tectonics.
7. The Earth has a layered structure with a dense metallic core, hot convecting mantle, and a brittle crust.	Dahl, Anderson, and Libarkin (2005), King (2000, 2008), Libarkin et al. (2005b), Lillo (1994) and Marques and Thompson (1997b) commonly report students struggle with thickness of Earth’s layers as well as physical state and density changes with Earth’s depth.
8. Earth’s interior is heated primarily by radioactive decay and gravitational energy.	Libarkin and Anderson (2005a) report students think Earth’s hot interior is due to insufficient cooling rather than energy from radioactive decay.
9. Rocks are chemically and physically weathered into smaller pieces which are transported (eroded) by gravity, water, ice, and wind.	Dove (1997) reports students use weathering and erosion interchangeably, and equate erosion with displacement of mass.
10. Soil is formed by weathered rocks and decayed organic materials.	Happs (1984) reports students do not conceive of soil as reflecting parent bedrock nor identify organics when thinking about what constitutes soil. Students believe soil was formed as the point of Earth’s formation, is miles deep, and does not evolve.
11. Landforms result from the interplay between processes that create crust (plate movement, crust uplift, and sedimentary rock formation) and those that destroy crust (weathering and erosion). These interactions occur at a variety of time scales.	Trend, Everett, and Dove (2000) report students struggle with vocabulary due to cultural and geographic variation among common vernacular. Rivers always flow north to south or west to east rather than downhill. Marques and Thompson (1997b) report topography due to shrinking and cracking of a cooling Earth.

Earth’s crust is broken into plates, which slowly move in relationship to each other, driven by convection currents in the mantle

Unquestionably, plate tectonics is the central theory of geology. To explore students’ understanding of plate tectonics, Marques and Thompson (1997a) conducted lengthy interviews with ten 16–17 year old students in Portugal leading to a written questionnaire of 270 students. They found that 21% of study participants believe Earth’s plates are something easily observable. Additionally, they report that 64% of students believe the Earth’s plates are arranged like a stack of layers. Curiously they found that 35% of students describe Earth’s plates as rotating around a central axis. Moreover, 43% of students inaccurately describe plates as progressively sloping from the centre of the continents to the bottom of the oceans.

Studying 61 in-service science teachers attending professional development workshops in the UK, King (2000) analysed questionnaire responses. Nearly half of his teacher participants misunderstood the scale of Earth’s crust relative to the entire Earth nor had appreciable understanding of how changing earthquake depths support the theory of plate tectonics. This result is consistent with that reported by Steer, Knight, Owens, and McConnell (2005) and Dolphin and Benoit (2016). Misunderstanding the depth scale of Earth’s plates potentially leads to misconceptions about the plausibility of plate tectonics.

Most recently McDonald et al. (2019) identified students’ misconceptions around plate tectonics using a learning progressions approach. After conducting 309 conceptual interviews with middle school students, they found that although most students understand that plates move, they have difficulty understanding the dynamic system of plates (system motion). The authors identify this as ‘a system of plates has been and will continue to be in motion at Earth’s surface’ (p. 89). When asking students what causes plates to move, many were able identify surface actors (e.g. waves and erosion), which the authors describe as a lesser productive understanding. However, only a few students were able to provide identify sophisticated reasons such as differences in heat and density in mantle material or recognising that the mantle is a convective system driven by heat.

It is perhaps surprising that so few empirical research studies on geology’s central theme of plate tectonics exist. As experienced geology teachers ourselves, we expected to find widespread in the literature the tacit notion shared by many of our colleagues that novice students frequently exhibit a natural preconception that the edge of continents represent the plate boundaries; yet, we found little empirical research in the literature clearly identifying this well-known misconception beyond McDonald et al. (2019), Dolphin and Benoit (2016), Ford and Taylor (2006), and Marques and Thompson (1997a).

Plate boundaries

Geologic events occurring at plate boundaries provide geologists with a glimpse of what is going on beneath Earth’s surface.

Sibley (2005) asked 602 students to sketch a cross-section of a continent-continent convergent boundary. Only 14% could do this correctly, even after instruction. The most common misconception revealed by the drawings were that 23% of college students the colliding plates bowing upward making an inverted V-shape. Some of these students drew and labelled magma upwelling between the colliding plates. Another 13% of students drew two colliding plates where deformation only occurred on the top side. These are illustrated in Figure 1 adapted from Sibley (2005). He went on to obtain drawings from 21 upper-level geology majors and found one-half also exhibited these misconceptions.

Figure 1. Students’ drawings of a continent-continent convergent boundary demonstrating two common misconceptions reproduced from Sibley (2005).

Clark, Libarkin, Kortz, and Jordan (2011) provided 60 undergraduates in introductory geology courses with a traditional, coloured, textbook diagram of an ocean basin surrounded by subduction zones without any labels and, with little direction students were asked to label as many features as they could, after receiving instruction. Of those 30 who chose to label subduction zones all students labelled it correctly (Table 2).

Table 2. Summary of Clark and Libarkin (2011).

Confuse spreading ridge with hotspot

Don’t know which is convergent or divergent without arrows

They don’t identify crust under oceans, just continents

Think melting only occurs deep, not at wedge too

Think melting is due to high temperature rather than pressure

Think melting is due to deformation collisions rather than change in chemistry or energy

Atoms of different elements combine to make minerals, which combine to make rocks. Rocks and minerals are classified by their chemical and physical properties

Rocks and minerals serve as a ready entry point into the study of geology because students can tangibly touch and categorise rocks with limited abstraction. Yet, learners seem to struggle significantly with naming rocks or understanding their classifications. In a traditional, single group post-test only study, Dove (1996) found when asking 84 pre-service teachers to write down from memory as many rocks as they could remember that students remembered very little. Moreover, few students could identify half of 14 specimens provided. When conducting follow up interviews, she discovered students rarely identify naturally occurring rocks as the basis of building materials or energy resources (e.g. slate, marble, coal). Further, rocks were characterised only by their surface features.

In a qualitative study using video recordings to classify students’ observation skill levels, Remmen and Frøyland (2019) found that when asking 55 twelfth-grade students to classify rocks into three major categories, their observation skills varied. Four student groups’ use of observation skills were more scientific (expert), noticing and describing relevant features and then using those features to classify specimens in major rock categories and at higher hierarchical levels. The remaining fifteen student groups used transitional observation, where they tried to recall the names of rocks rather than noticing important features. There were no student groups that used every day (novice) observation.

It’s generally recognised that students do not carefully differentiate between the words rocks and minerals. Ault (1982) found that primary students associate a crumbly texture or darker colour as being indicative of the oldest rocks. Ford (2003) reports that most of the 55 middle school students studied believe rocks are characterised on the basis of their shape. Nearly one quarter focus on superficial physical characteristics when categorising rocks, like shape. This is similar to Happs’ (1982) report that students simply characterise rocks based on their weight. Moreover, students Happs studied incorrectly associate the word mineral with the notion of vitamins.

Monteiro, Nóbrega, Abrantes, and Gomes (2012) developed and administered a two-tier diagnostic instrument to 89 twelfth-grade Portuguese students’ to identify misconceptions about minerals. They found that that 49.4% of students believe glass is not a mineral because it is an artificial crystal, not because of its internal organisation. Few participants (23.6%) think that all crystals should be shiny and translucent therefore, therefore thinking not all minerals are crystals. Some participants (24.7%) believed that artificial diamonds were minerals because their crystalline structures are the same. Overall, the authors found that students struggle with the concept of minerals and as a result have developed many misconceptions.

Schoon (1992) found using a questionnaire containing common science alternative conceptions that 54.4% of fifth graders believe that any crystal that scratches glass must be a diamond. He reports that the frequency of this alternative conception reduces with age but does not disappear. Schoon (1995) reports 16.4% of 122 pre-service teachers still believe that any crystal that scratches glass must be a diamond.

The nature of Earth’s fossil fuels seems to engender its own set of misconceptions. Lillo (1994) found high school students believe that natural resources are found only in the deepest layers of Earth, and not in the near surface crust. Dove (1996) reports that pre-service teachers often think of natural resources as being a different category than rocks. Leather (1987) reports students believe oil collects in caves under the ocean or forms from coal. Rule (2005) found many students believe that oil is made from dirt and soil or molten metal. Alternatively, Rule (2005) found some of his subjects believes oil came from dinosaurs. Table 3 provides a sample of the most frequent misconceptions about natural resources Rule (2005) found.

Table 3. Sample of Rule (2005) identified misconceptions.

Misconception	Frequency
Oil is used mostly for lubrication	40%
Oil fills an otherwise empty cave, pit, hole, lake or stream underground	46%
Gasoline is stored inside the rectangular pump at a gas station	32%
People don’t have oil wells in cold places	15%
Oil is important mostly to people who sell it	21%
There is no oil under desert area	19%
Cooking oil comes from petroleum	28%
People can find diamonds in coal	22%
Oil is evenly distributed over the Earth	22%
There is no oil under the ocean floor	18%
Gasoline is being mined under gas stations	13%

Earth materials take many different forms as they cycle through the geosphere. Rocks form from the cooling of magma, the accumulation and consolidation of sediments, and the alteration of older rocks by heat, pressure, and fluids. These three processes form igneous, sedimentary, and metamorphic rocks

A key concept in geology is that Earth’s materials cycle from one form to another. This notion is generally called the rock cycle. Kali, Orion, and Eylon (2003) studied systems thinking in the context of the rock cycle. Their results suggest that having a meaningful understanding of the rock cycle requires high levels of system thinking. 40 seventh-grade students enrolled in a selective Israelian school were asked four open-response questions, one in a familiar context and three in a novel or new context. The questions asked students to identify and describe a sequence of processes that produce various types of rocks. Student responses were analysed as either positive (geological processes are mentioned and in a correct sequence) or negative (the rock cycle is not viewed as a dynamic system). Results show that the majority of students (66%) were able to successfully reconstruct a relatively large sequence of processes that can produce sandstone from exposed granite. Kusnick (2002) also reports that rocks are always formed where they are found (e.g. rocks found in rivers must be sedimentary) and rocks are formed by catastrophic events such as earthquakes. One third of his study participants consistently show misconceptions like those listed above.

Stofflett (1993) found using interviews and a pencil and paper test that pre-service teachers struggled mightily with accurate conceptual models of the rock cycle. One reason students struggle with the rock cycle is that students intermingle the rock cycle with weathering processes. Out of 30 pre-service teachers she reports 11 students attributed igneous rock formation to weather conditions, 12 students thought that metamorphic rock was formed by weather conditions, but only seven students attributed the formation of sedimentary rocks to weather conditions. An illustration of her test is shown Table 4. This result is similar to that reported by Oversby (1996) who found that students believe minerals are always created through pressure. King (2008) reports students conceptualise the rock cycle as taking millions of years to occur. The biggest challenge to educators teaching the rock cycle seems to be that students conceive of the rock cycle as a causal mechanism for rock formation rather than a model showing relationships between rock categories (Ford, 2003, 2005).

Table 4. Sample of ‘Rock Test’ items reproduced from Stofflett (1993).

Look at rock #1 and answer these questions: [Granite]* In what environment and under what conditions did it form?** Why are the grains different colors? What causes this rock to form? What kind of rock is this? (circle)

Igneous   Sedimentary   Metamorphic

(2) Look at rock #2 and answer the following questions [Sandstone]* In what environment and under what conditions did it form? Why are the grains the same size? What made the grains stick together? (What process?) What kind of rock is this? (circle)

Igneous   Sedimentary   Metamorphic

(3) Look at rock #3 and answer the following questions [Granitic gneiss]* In what environment and under what conditions did it form?** What made the stripe-like feature form? How is the process of this rock’s formation different from rock #1? What kind of rock is this? (circle)

Igneous   Sedimentary   Metamorphic

Put an X next to all the statements you agree with

___ Igneous rocks can become igneous rocks.

___ Igneous rocks can become sedimentary rocks.

___ Igneous rocks can become metamorphic rocks.

___ Sedimentary rocks can become igneous rocks.

___ Sedimentary rocks can become sedimentary rocks.

___ Sedimentary rocks can become metamorphic rocks.

___ Metamorphic rocks can become igneous rocks.

___ Metamorphic rocks can become sedimentary rocks.

___ Metamorphic rocks can become metamorphic rocks.

Metamorphic rocks are those created from other rocks by intense heat and pressure. In contrast, both Oversby (1996) and Stofflett (1994) report that pre-service teachers frequently believe that all minerals are created under pressure, not just metamorphic rocks. Specifically related to the formation of metamorphic rocks Stofflett (1994) reports students often misinterpret layers of foliation due to metamorphic processes as being caused by sedimentary depositional processes. In contrast to metamorphic rocks, sedimentary rocks are created from other rocks by weathering and erosion processes. When asking 111 pre-service teachers what causes grains composing sedimentary rocks to stick together, Stofflett (1993) received 44 different responses. The most common responses were: pressure (29%), heat (7%), erosion (6%), and chemical bonding (5%).

Earth’s rocks allow us to reconstruct Earth’s history, giving both relative and absolute dates

The notion that Earth is about 4.6 billion years old has only been widely accepted in the last hundred years. Few studies on students understanding of Earth’s history were done prior to the turn of the century. Libarkin et al. (2005b) report that less than half of 370 college undergraduates across four institutions were able to state Earth’s accurate age. A significant number of those they studied were unable or unwilling to provide numerical answer at all saying things like: Earth formed a long time ago or Earth formed back in the dinosaur age. Hidalgo, Fernando, and Otero (2004) found similar results in high school students and college students.

Marques and Thompson (1997a) found that students ages 10–11 tend to describe the time since geologic events in thousands of years, whereas students ages 14–16 describe geologic events as occurring millions, billion, and trillions of years ago. They report only 7.2% of 493 students they studied were able to provide an accurate age of the Earth. Catley and Novick (2009) asked 126 students to provide ages for common geologic events (e.g. when did dinosaurs become extinct). They found their participants gave startling wide and inaccurate time ranges. They conclude that college students lack a conceptual framework to make sense of ancient events.

The most widely recognised work to date has been done by Trend (1998, 2000, 2001). Trend (1998) conducted paper and pencil surveys with 177 ten- and 11-year olds in the United Kingdom. He found students generally cluster geologic events into two distinct time zones, less ancient and extremely ancient. His participants had a general awareness of major geologic events but no clear chronology. Trend (2000, 2001) found that 51 in-service teachers and 179 pre-service teachers he studied generally divide geologic events into three distinct time zones, instead of two. These individuals cluster geologic events as being extremely ancient, moderately ancient, and less ancient. He reports that within these categories, teachers lacked any consensus on absolute or relative dates.

At the same time, many students struggle with concepts related to radioactive dating. Prather (2005) reports students have deeply entrenched misconceptions about half-life and radioactive decay. His interviews with college students revealed that students often equate radioactive decay and disintegration of matter. Similarly, Petcovic and Ruhf (2008) report only 25% of college students correctly answered questions about radioactive decay on a pre-test, and disappointingly increased to 41% correct after instruction.

Trend (1998, 2000, 2001) made use of a card sorting method where participants were to sequence geologic events. On one hand, he found that participants were able to correctly sequence the universes’ earliest events such as big bang, formation of the sun, formation of Earth, first rocks. On the other hand, he found participants struggled mightily with correctly sequencing life-oriented events such as first fish, first plants, first wooly mammoths. DeLaughter, Stein, Stein, and Bain (1998) found that 25% of 149 college students completing open-student-response surveys gave answers that showed Earth’s formation and the appearance of life was simultaneous. Their results are similar to Marques and Thompson (1997b) who reported that half of their 493 (10–16-year old Portuguese) participants state that Earth’s formation and the appearance of life were simultaneous. Libarkin et al. (2005b) reported that more than 30% of their 370 college undergraduate participants across four institutions also believed that certain life forms existed at Earth’s formation such as single-celled organisms and aquatic organisms.

Whereas the above research focused on absolute ages, some research exists focusing on relative ages. The guiding principles of solving problems related to relative age are uniformitarianism, and the principles of superposition and original horizontality. Ault (1982) argues that children can use the principle of superposition successfully as early as grade two. Dodick and Orion (2003) used an assessment known as the GeoTAT to show that students will inappropriately evoke the principle of original horizontality. Figure 2 shows an item from the GeoTAT that many students answer incorrectly because they assume that depth below the surface is of paramount importance.

Figure 2. GeoTAT Puzzle #1 reproduced from Dodick and Orion (2003).

Dodick and Orion (2003) also report that students often fail to understand that environmental conditions can change drastically at the same location over long periods of time. In much the same way students apply the concept of uniformitarianism inappropriately (Shea, 1982) and often conceive of depositional environments to exhibit a constant rate of sedimentation across great expanses of time.

Fossils provide evidence about the types of organisms that lived long ago and the nature of the environments at the time

The role of fossils in understanding the Earth’s ancient climate and environmental conditions are central to historical geology. At the same time there exists almost no systematic research into students’ conceptions of fossils. The most cited misconception is that a surprisingly large number of students believe dinosaurs and humans coexisted. Schoon (1992) reports 32.6% of the 1,213 students and adults he studied are committed to this incorrect idea. Schoon and Boone (1998) studied 619 study pre-service elementary teachers and found that many also exhibit this misconception. Gosselin and Macklem-Hurst (2002) found that college students could improve their understanding from 30% believing this idea on a pre-test to only 7% answering this away after targeting instruction. Fifty years earlier Ralya and Ralya (1940) reported 22% of 325 college students believe that fossils are the remains of animals drowned during The Flood.

Whereas the overarching importance of fossils are related to understanding environmental conditions and establishing relative ages most of the research on student understanding is related to the less important nature of fossilisation. Oversby (1996) describes pre-service teachers’ misconceptions that only living things, like plants and animals, have undergone fossilisation, are considered fossils. In other words, an unfossilised shark tooth or a mould an animal track would not be considered a fossil. Petcovic and Ruhf (2008) report college students struggle answering questions about fossils, only increasing from a 61% correct on a pre-test to 78% correct after instruction (Figure 3).

Figure 3. Fossil questions used by Petcovic and Ruhf (2008).

Dodick and Orion (2003) studied 285 Israeli students. They report that students believe fossils will disappear or deteriorate over time. Moreover, their research reveals that students believe the age of a fossil is directly related to its complexity, with the most complex fossils being the most recently deposited.

Earthquakes, mountain building, volcanic activity, and ocean floor features occur at plate boundaries as the result of plate movement

Earthquakes

Much of the education research on earthquakes focuses on their uncovering the causal mental models that students employ. Francek (2013) cites Leather (1987) as reporting middle school student believing earthquakes are energised by heat and weather. This accounts, he suggests, that students believe earthquakes occur only in equatorial hot climates. As a result, he reports students believe earthquakes are not likely in northerly latitudes like Britain. College students and elementary school students also exhibit this misconception about earthquakes occurring in warm climates (DeLaughter et al., 1998; Sharp, Mackintosh, & Seedhouse, 1995).

Libarkin et al. (2005b) gave an open-ended questionnaire to 235 undergraduate college students about earthquakes and their causes. Twenty-seven students gave answers that did not mention plate tectonics or faulting in written responses. Alternative explanations for the primary causes of earthquakes were volcanoes, air pockets, climate, heat, and mammals.

Simsek (2007) describes a study of 40 primary school students in Turkey where 16 had felt earthquakes. Using a semi-structured interview, she found young students invent a wide variety of causal mechanisms for earthquakes. These include: because children light a fire and forget it; boiling water underground; landslides; upwelling water; lightening; winds; heavy rain; cracking of underground material; and air pressure pushing down on the ground. Tsai (2001) also studied students who were familiar with earthquakes, many of which who experienced a 7.3 magnitude earthquake in Taiwan during 1999. She tracked ideas about earthquakes of 60 fifth and sixth graders using interviews. She reports students believe earthquakes can be caused by changes in gravity or by electromagnetic fields and 35% believe they are caused by supernatural forces.

Schoon (1995) administered questionnaires to 122 pre-service elementary teachers and 307 fifth graders. To determine if participants knew that there are global patterns in where earthquakes most often occur, he asked if Chicago had a high probability of being severely damaged by an earthquake. 68% of pre-service teachers and 64.5% of fifth graders responded that Chicago was at high risk for a severe earthquake. Ford and Taylor (2006) interviewed 26 middle school students and report that a common misconception is that students think earthquakes occur most frequently along coastlines, without regard to the location of plate boundaries. His results imply participants believe earthquakes can readily occur at any location. At the same time, he found that 12% of pre-service and 18% of fifth graders believe earthquakes can be accurately predicted by observing the behaviour of wild animals. A study in the same year by Coleman and Soellner (1995) reports 64% of 40 college students in their study initially thought earthquakes might be able to be predicted but largely change their minds after applying systematic scientific investigation principles during targeted instruction.

Volcanoes

The scholarly literature often tightly connects concepts surrounding earthquakes with volcanoes. For those experts who understand plate tectonics as unifying theory such connection is sensible. In contrast, novice learners typically view earthquakes and volcanoes as separate and only mildly connected phenomena, and not tightly tied to plate tectonics (Libarkin & Anderson, 2005a). Barrow and Haskins (1996) administered a questionnaire to 186 college students prior to college level instruction – it was assumed that all students had experienced at least a modicum of Earth science instruction during their K-12 learning experiences. When asked why earthquakes and volcanoes are often studied together, 17% of students described that earthquakes cause volcanoes, mostly because earthquakes force lava upward. Only 6% suggested that volcanoes form when plates collide or occur at plate boundaries.

Other researchers have reported students’ inclination to associate volcanoes (and earthquakes) as being co-located in hot or equatorial regions (DeLaughter et al., 1998; Happs, 1982), as cited in Bezzi and Happs (1994); Libarkin and Anderson (2005a); Leather (1987); Parham et al. (2010). Bezzi and Happs (1994) conducted a survey of 990 (14–16 year old) students from 37 across northern Italy and discovered that few students can accurately identify whether or not they actually live in a volcanically active area. They attribute such misconceptions to mass media based on their surveys.

Volcanoes are often depicted in movies and television as catastrophic eruptions with overwhelming flows of lava. A sizeable minority of students believe magma originates in Earth’s core (Bisard, Aron, Francek, & Nelson, 1994; Dahl et al., 2005; Libarkin & Kurdziel, 2006). Cheek (2010) suggests this could be a result of textbook illustrations of large convection cells commonly used in the teaching of geology. Similar to results by Barrow and Haskins (1996), 32% of students in Parham et al.’s (2010) study cite seismic activity as the driving mechanism for volcanic eruptions.

King (2008) describes how authors often contribute to students’ misconceptions by describing that Earth’s crust floats atop on ocean of magma. Dal (2007) finds in his study of 120 (13–14 year old) students from inner-city schools in France that students believe magma occupies the entire interior of Earth. King (2008) reports that authors describe volcanoes as places where magma is squeezed and forced upward through cracks in Earth’s surface rather than the scientifically accurate model where less dense magma rises due to buoyancy. Using these mental models, it seems reasonable for novice learners to conceive of volcanoes as ruptures exposing Earth’s molten interior. King (2000) provided 76 in-service teachers attending a professional development workshop with a map of volcano distributions. 29% were unable to indicate which volcanoes are likely to have magma of mantle origin and which have magma of plate-melt origin. These findings lend weight to the notion that students’ emerging mental models of plate tectonics and volcanoes are not solidly interconnected.

Ocean floor features

Even the most rudimentary ideas surrounding continental drift suggest that seafloors can spread. As experienced geology teachers ourselves, we expected to find numerous references to the tacitly known misconceptions novice student naturally adopt that divergent plate boundaries result in deep chasms at the bottom of the ocean, rather than submarine mountain ranges caused by upwelling magma. Ford and Taylor (2006) interviewed 26 elementary students and reported that students think there are large gaps or spaces between Earth’s plates. This seems to us to be surprisingly little empirical evidence that students hold this specific misconception which we assumed was widespread. We do not interpret our lack findings to mean that this particular misconception does not exist among students; instead, we suspect researchers have not allocated significant energy toward uncovering or documenting this notion and use its absence as a call for a fruitful line of inquiry in future discipline-based geology education research.

The Earth has a layered structure with a dense metallic core, hot convecting mantle, and a brittle crust

Because of Earth’s massive size learners have difficulty understanding the relative or absolute thicknesses of Earth’s constituent parts. Numerous education researchers report learners vastly overestimate the relative thickness of the crust (King, 2010; Libarkin & Anderson, 2005a; Steer et al., 2005; among others). As one example, King (2000) reports that 93% of 61 science teachers in the U.K. were unable to draw a reasonable thickness of the crust on a 44cm diameter Earth. Novice learners need to have an accurate understanding of just how incredibly thin Earth’s lithosphere is because it is difficult to conceptualise massively thick plates being able to move as a result of convection. At the same time, Clark et al. (2011) found undergraduate students were reluctant to label oceanic crust as readily as thicker, continental crust after instruction.

Experienced Earth science teachers know students struggle with understanding how the physical state or density of Earth’s layers change with depth (Dahl et al., 2005; King, 2000, 2008; Libarkin & Anderson, 2005a; Lillo, 1994; Marques & Thompson, 1997b). A significant number of students are unable to accurately identify the physical phase of either the core or Earth’s mantle. King (2000, 2008) reports many students conceptualise the Earth as a sphere of molten, liquid magma contained by Earth’s thick, solid crust. Clark et al. (2011) also report that college students in their study conceive of the mantle as being predominantly liquid.

Barnett et al. (2006) report studied 82 middle school students from a moderately diverse school district. Using a two-group pre-test/post-test comparison study design, they found that 74% of 50 students who watched The Core – a science fiction movies with questionable scientific accuracy held more misconceptions than 91% of 32 students who did not watch The Core as part of instruction. Even without the isolated influence of inaccurate science fiction movies, McAllister (2014) found that 22% of the 92 undergraduates she interviewed have no coherent conceptual model of Earth’s interior that reflects current scientific understanding. In fact, only 9% of the 92 undergraduates could describe and sketch comprehensive conceptual models that were accurate. These results are similar for international students studied by Capps, McAllister, and Boone (2013). For students to understand the dynamics of a convection driven plate tectonics model, a required perquisite understanding is an accurate conception of Earth’s interior, both in terms of concentric layering and variable density.

Earth’s interior is heated primarily by radioactive decay and gravitational energy

Experienced geology teachers know that when students are first taught that Earth’s interior is hot and that certain layers are molten, many students create a new misconception that this is a result of Earth not being finished completely cooling from its initial formation. It seems that students do not consider radioactivity to be an important heating energy source. There appears to be almost no systematic exploration of this common misconception in the literature. Not even Franceks’ (2013) compilation of over 500 geoscience misconceptions touches on this idea. However, as a testament to the importance of this idea one of the questions from Libarkin and Anderson (2005a) geoscience concept inventory is devoted to capturing the range and domain of this misconception. No other empirical evidence for this misconception was uncovered in our literature survey. This is an area deserving of future education research effort.

Rocks are chemically and physically weathered into smaller pieces which are transported (eroded) by gravity, water, ice, and wind

Given the widespread importance of concepts surrounding weathering and erosion, it is perhaps surprising that there exists few empirical research studies about student conceptions of weathering and erosion. By far, the most cited research is that by Dove (1997). Dove (1997) studied 236 A-level geography students at seven college and schools in the U.K. She asked them to provide definitions and distinctions between weathering and erosion. She found many students use weathering and erosion interchangeably. When looking at students who distinguish between the two incorrectly, the common mistakes were: (1) Ascribing weathering to weather related events (e.g. wind and rain); (2) Ascribing erosional events because they were unconnected to weather; (3) Ascribing weathering as being chemical in nature; and (4) Ascribing erosion as being physical in process. As one example, in the case of plant roots, two-thirds of students ascribed this to weathering because the plant and the rock remaining in situ. Blake* (2005) and Martínez, Bannan, and Kitsantas (2012) also touched on students’ conceptions of weathering and erosion in the context of much larger studies; however, their results provided only limited insight into the underlying mental models students hold directly related to weathering and erosion. This deficit in research provides fruitful avenues for future research studies (Table 5).

Table 5. Sample of misconceptions identified by AAAS (n.d.) with percentages of middle school students and high school students holding the misconception respectively.

Misconception	Middle school students	High school students
The growth of plant roots cannot break rock	45%	38%
Wind cannot carry rock and deposit it into a new location	31%	32%
Water cannot dissolve rocks	29%	24%
Water cannot carry rocks and deposit them in a new location	23%	22%
Ice can only break a rock when it moves (as in a glacier)	23%	18%
The small loose rocks on the surface of the Earth were never part of the solid rock layer	50%	45%
Water can wear away only a small amount of a mountains height (feet or inches) over millions of years	55%	53%
Erosion can wear away solid rock a little bit, but could never have a big effect on the surface of Earth such as levelling mountains or carving valleys	11%	10%

Soil is formed by weathered rocks and decayed organic materials

Hayhoe (2013) argues that there has been very little research on soil science education despite its’ widespread appearance in curriculum. He conducted a thorough review of soil science education curriculum materials and instructional suggestions and found that students and teachers have surprisingly little conceptual framework regarding soil science. The most systematic empirical study was done by Happs (1984) where he studied 40 college students in New Zealand using clinical interviews. 43% of the students he studied used the words ‘dirt’ and ‘soil’ as synonyms, and those that do distinguish have highly varying criteria. Almost every student describes soil as having the ability to support plant life, which is somewhat in conflict with the dominant scientists’ viewpoint that soil is a product of the environment comprising mineral and organic constituents.

Happs (1984) found that 53% of students think that soils are formed contemporaneously with the formation of Earth. At the same time, students have widely varying conception about soil depth. 33% of students thought the average depth of soil was about one metre; whereas, 13% thought that soil is typically at least one kilometre deep or more. In terms of soil evolution, 23% failed to suggest that soil changes over time.

Landforms result from the interplay between processes that create crust (plate movement, crust uplift, and sedimentary rock formation) and those that destroy crust (weathering and erosion). These interactions occur at a variety of time scales

Concepts and vocabulary surrounding landforms are widely included in geology, geography, and agricultural education curricula. Teaching students about landforms is challenging because the vocabulary surrounding landforms is often imprecise and idiosyncratic (Trend et al., 2000; Wiegand, 1993). What is a pond versus lake, creek versus stream, and even hill versus mountain are often based on historical contexts and local cultures–making these ideas confusing and difficult for many students. As a result, the systematic and empirical research in the scholarly literature is exceedingly difficult to summarise in meaningful ways. Rule, Graham, Kowalski, and Harris (2006), among other authors, provide numerous citations describing competing teaching methods for helping students learn landform vocabulary.

Most recently, Jolley, Jones, and Harris (2013) developed the Landscape Identification and Formation Test (LIFT) to measure student’s knowledge of landscapes and their formation timespans. They found that students often misidentify common landscapes and features which also leads to students incorrectly estimating the formation timespan for that particular landscape or feature.

Francek’s (2013) report on 500 misconceptions lists only karst topography when discussing landforms. Kastning and Kastning (1999) have devoted considerable effort to helping outreach and extension educators to become aware of widespread misconceptions about caves and karst topography. They define karst as a landscape that is principally formed by the dissolving of bedrock. For clarity, it is useful to add that karst is characterised by sinkholes, caves, dry valleys (little or no surficial drainage), sinking streams, springs and seeps, solution valleys, and various forms that are sculpted on the bedrock surface (collectively known as karren). They disseminated common misconceptions (shown in Table 6) about karst topography they acquired through years of outreach and extension education; however, they, like many other educators working tirelessly in the domain of landform education, provide no systematic research studies in contribution to the scholarly literature. Even Marques and Thompson (1997b) allocate only one sentence to landform education, stating that 40% of 270 Portuguese high school students they studied believe that the cooling [and shrinking] of Earth results in the appearance of topography. Students understanding of how rivers, mountains, caves, volcanoes, valleys, deserts, and canyons form and evolve over time remains largely unstudied systematically by geology education researchers, although some decades-old and only tangentially related work in geography education does exist (Nelson, Aron, and Francek, 1992) and were seemingly included in Francek’s (2013) later work.

Table 6. Common misconceptions about karst (Kastning & Kastning, 1999).

Bedrock is solid, without voids Water enters sinkholes because they are there, rather than water creates sinkholes Pollutants put into the ground in karst remain where they are placed Water from karst springs is pure All sinkholes form catastrophically Karst is always well expressed on the surface Caves form by erosion Caves are as old as the rocks they are in Groundwater flow in karst is simple and direct

Conclusion

Our driving question for this work was which common geology misconceptions are well poised to interfere with teaching the geology concepts identified by a consensus of U.S.-based national standards and frameworks reform documents. Our primary conclusion is that, when considering the existing landscape of geoscience research literature as related to the consensus of ideas commonly proposed for geology standards and frameworks, it is abundantly clear that some conceptual domains have been studied excessively while others are in still in dire need of study. These results have identified what many of those misconceptions are, but certainly not all. In other words, we do not yet have the final, comprehensive list of geology misconceptions that constructivist-oriented educators need to design the needed curriculum, instruction, and assessment. The most commonly described student misconceptions are that students do not understand the scale of Earth, the scale of Earth’s history, or the physical processes that occur at active plate boundaries. These are likely critical for a comprehensive understanding of geology. The least studied areas are perhaps those that are most concrete and tangible for students – soils and landforms. These results provide part of a pathway for a future geoscience education research agenda.

This work certainly provides ideas for potentially unexplored yet fruitful avenues for future discipline-based geoscience and geocognition education researchers–for example in student understanding of evolving soils–and at the same time suggests boundaries for domains that may have already had considerable research conducted and published–for example when considering student understanding about the nature of plate boundaries. Moreover, this work provides some pointers to important science education research results beyond what has been done in the U.S. of which many novice researchers may be naively unaware.

In addition to outlining some broad scientific domains for needed geoscience education research efforts, this work provides some important insights to curriculum developers. Modern curriculum designers are largely committed to student-centered learning and taking students a priori ideas into account instead of treating students as tabla rasa blank slates. As a community of scholars, we generally accept the notion that our students’ pre-existing conceptions can be well poised to interfere with even the most cleverly designed instructional materials. Highlighting the internationally methods and results found in the reviewed works here can serve designers to make more useful curriculum materials.

At the same time, classroom teachers themselves benefit from knowing how students often think about geology concepts. The details of this work here provides classroom teachers with important information on guiding classroom instructional decisions to help students navigate the complex scientific concepts inherent in learning about geology. In much the same way, this work provides insights to commonly held misconceptions that assessment designers and test item writers need to be aware of when trying to carefully design assessment instruments to uncover and categorise student thinking and measure the effectiveness of instructional strategies across large scales.

Taken together, the wide-breadth of research summarised here also serves as an important resource to policy makers and future education standards designers. Even beyond having identified which ideas are core across many standards-revision and curriculum-reinvigoration efforts, this work helps to expand the all too often U.S.-centric thinking of U.S. education standards designers to have more of an international perspective, thus being able to provide a more inclusive perspective for the wide diversity of U.S. students, and beyond.

Much of the repeated insufficiency in the existing literature landscape clearly shows an obviously pronounced emphasis on memorised vocabulary – what’s the difference between and hill and a mountain? – as compared to studying which mental mechanisms students use when thinking about our dynamic planet. For example, we know that students do not connect the study of volcanoes with the paradigm of plate tectonics, but the research provides almost no insight as to why this is true. The next dramatic leap forward in understanding how to best teach geology will likely require a thorough understanding of the conceptual models students use. The bottom line here is that knowing which misconceptions are prevalent is extremely helpful to the constructive-oriented educator, but very little of the literature yet goes on to the next step of trying to explain from a cognitive-point of view why students think as they do, let alone how to combat that thinking in the modern classroom.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Sarah K. Guffey http://orcid.org/0000-0002-9074-901X