Optical Pulsars and Black Arrows: Discoveries as Occasioned Productions

Abstract

The current article represents a methodological proposal. It seeks to address the question of how one might recognize a discovery as a discovery without knowing in advance what is available to be discovered. We propose a solution and demonstrate it using data from a study previously reported by J. Roschelle (1992). Roschelle investigated 2 students' developing understandings of certain abstract features of Newtonian mechanics while working within a computer-based microworld, the Envisioning Machine. We employ an approach we term discovery as occasioned production to reexamine his data. Such an approach proceeds stepwise from the identification of some matter discovered, working backward to see just where that matter entered the conversation and then, finally, tracing from that point forward to illuminate how the proposal for a possible discovery was ultimately transformed into a discovery achieved. The notion of “evident vagueness,” borrowed from H. Garfinkel, M. Lynch, and D. Livingston's (1981) account of the discovery of an optical pulsar, emerges as an important feature of our analysis. Following H. Garfinkel (2002), we present our findings as a “tutorial problem” and offer a suggestion for how a program of practice studies in the learning sciences might be pursued.

Notes

¹Roschelle described Dana and Carol's achievement in terms of conceptual convergence. Our unmarked shift from talking about conceptual change to talking about discovery is consistent with usage within the learning and cognitive science communities that seems to employ these terms interchangeably. Thagard (1992) and Dunbar (1994), for example, described scientific discovery in terms of conceptual change. In the same vein, Strike and Posner (1985) described all learning from a constructivist perspective as conceptual change.

²The foundations of conversation analysis research were presented in the Sacks (1992) lectures. Consult ten Have (1999) or Schegloff (2006) for useful introductions to the methodology.

³A broader question with high relevance to the learning sciences concerns how we might adapt our research practices to treat not only discoveries in discovery learning but all forms of instruction as “occasioned productions”? We return to this later.

⁴Taylor was listed as the third author on the Cocke et al. (1981) report announcing the discovery. In addition to designing the instrument that made the discovery possible, he had participated in the observations done on nights prior to the one on which the discovery was made and rejoined Cocke and Disney on the evening following the discovery.

⁵For additional discussion of the role of equipment in discovery practices, see Latour and Woolgar, 1979; Lynch, 1985; Pickering, 1995; and Traweek, 1988.

⁶The transcription conventions are summarized in Appendix A. If this notation is unfamiliar to you, you might find it helpful to read the transcripts aloud with a partner. Try to attend, as you do so, to all of the marked features of timing and delivery. It has been argued that transcripts are, in their design, theory-laden (Ochs, 1979). Transcriptions can be easily modified to conceal the identities of the subjects and readily lend themselves to presentation on a printed page. They have, as a result, historically been the stand-in of choice for vocal practice in the literature on language and social interaction. They work best when the analysis focuses chiefly on talk and less well when embodied aspects of interaction are considered. Nonetheless, they are an important tool for reconstructing an analyzed event and that is how they are used here.

⁷ Lynch (1993) reported that a “brief telegram announced their findings simply by formulating the date and time, period of the pulse, celestial coordinates, and identity of the ‘source’ star in the Crab Nebula” (p. 213) was dispatched to other observatories around the world. Other astronomers were soon able to replicate Cocke and Disney's finding and locate additional examples of optical pulsars. Lynch found it remarkable that they were able to do so using such sparse instructions.We find it also interesting that the sighting of one optical pulsar made pulsars suddenly visible to all.

⁸Though he does not appear in either of the quoted excerpts, it should be remembered that the night assistant, Robert McCallister, was also present on the telescope platform. Although the dialogue would suggest that Cocke and Disney were both monitoring the CAT display, we do not knowif it was also available to McCallister. There are many aspects of this activity that are unknown to us: How were the participants positioned with regard to one another? What displays and gauges were available to each? Were their hands free for pointing and gesture, and were they used for such? Despite these large gaps in our record, however, it is still possible to make certain grounded claims regarding the organization of the discovery talk.

⁹Linguists refer to such verbs as copulas.

¹⁰See Arminen (2008) for further development of this connection.

¹¹For a related notion, see Garfinkel and Sacks's (1970) discussion of “Rose's gloss” (p. 366). While driving through a city that he was visiting, Rose looked out the window and said to his host, “It has certainly changed.” By leaving it open in this way, Rose was able to work out just what he was in fact looking at (and thereby specifying) by locating it in his interlocutor's reply. As Garfinkel and Sacks argued, the “definiteness of circumstantial particulars consists of their consequences” (p. 366, italics in original). The connection of Rose's gloss to the Sacksian IT was suggested by John Heritage (personal communication, April 11, 2007).

¹²The term is borrowed from Garfinkel and Sacks (1970), who specified that something is a mock-up precisely in the ways in which it serves to give “an account of an observable state of affairs” (p. 363). That is, it must both provide for “an accurate representation of some relationships and some features in the observable situation” but, at the same time, make “specifically and deliberately false provision of some of the essential features of the situation” (p. 363, italics in the original).

¹³We refer to the light and dark arrows as the vel and acc vectors, respectively. We do so as a notational convenience, but with a certain amount of trepidation. Such labels allow us as auditors to recover the sense of the display as an animated form of vector arithmetic. It is easy to be seduced, however, into presuming that the participants might have also understood these representations in this membered way. So beware.

¹⁴One might note the similarities between Heritage's (2005) description of changes in cognitive state as “processual” and “one that dawns, emerges, and consolidates” and our earlier discussion of discovery-in-progress.

¹⁵As mentioned earlier, the behavior of the vectors attached to the white ball differed in subtle ways from the behavior of the corresponding vectors in the VSD. One could actually visualize the acc vector that traveled with the white ball as “pulling” the tip of the vel vector (see Figure 3). Based on their affiliated gestures, however, Dana and Carol's talk appears to be oriented to the vectors in the VSD.

¹⁶The alert reader might have noticed that Carol's previously described proposal for a possible discovery (Excerpt 6) also employed a pre-announcement structure, one in which the Solicit Turn was preempted. Their proposals, therefore, had parallel organizations.

¹⁷See Dana's turn (lines 132–138) in Clip #9 in Appendix C.

¹⁸See Figure 8 (p. 253) in Roschelle (1992).

¹⁹It is interesting that it was Dana, not Carol, who articulated this understanding in the debriefing interview. This is possibly the strongest piece of evidence for the first form of convergence described by Roschelle (1992), that is convergence of their collective understanding of what they were doing together.

²⁰We thank one of the anonymous reviewers for suggesting this argument.