Refined metric for a-posteriori novelty assessments

Figures & data

Table 1. Generic set of ideas with ‘missing attributes'. Different ideas for each attribute (A1, A2, A3) are coded with a different symbol.

Idea	Occurrences	A1 solutions	A2 solutions	A3 solutions
C1	1	Α	X	Δ
C2	93	Β	Y	–
C3	2	Γ	–	–
C4	2	Γ	Y	–
C5	2	Γ	Z	–

Table 2. Individual novelty values calculated by applying $M_{SNM}$ and $M_{SNM}^{\mathrm{\prime }}$ on the generic set of Table 1.

Idea	$M_{\text{SNM}}$	$M_{\text{SNM}}^{\mathrm{\prime }}$
C1	6,60	6,60
C2	0,34	0,50
C3	3,13	9,40
C4	3,24	4,85
C5	6,40	9,60

Figure 1. Additional example to demonstrate how both SNM and SNM’ cannot correctly deal with missing attributes. Idea A appears 99 times, while Idea B only one time.

Table 3. Individual novelty values calculated by applying $M_{\text{SNM}}^{\mathrm{\prime }\mathrm{\prime }}$ on the generic set of Table 1. The values from $M_{\text{SNM}}$ are also reported for a direct comparison.

Idea	$M_{\text{SNM}}$	$M_{SNM}^{\mathrm{\prime }\mathrm{\prime }}$
C1	6.60	9.90
C2	0.34	0.43
C3	3.13	6.43
C4	3.24	3.33
C5	6.40	6.43

Table 4. Attributes (Att.) identified by the evaluators and related weights (W). From Fiorineschi, Frillici, and Rotini (2020b).

	Att.	Description	W
EV1	A1	Lateral increased support	0,16
	A2	Height adjustment	0,18
	A3	Number of moduli	0,09
	A4	Ground stand	0,11
	A5	Horizontal latch	0,11
	A6	Number of vertical beams	0,09
	A7	Lifting device	0,07
	A8	Frontal slope adjustment	0,18
EV2	A1	Adaptability (different configurations)	0,25
	A2	Other purposes	0,05
	A3	Stability of the system	0,25
	A4	Ease of transportation	0,2
	A5	Size reduction	0,25
EV3	A1	Elevating method	0,25
	A2	Size reduction method	0,15
	A3	Number of pieces to assemble	0,05
	A4	Additional functions	0,25
	A5	Transport	0,15
	A6	Ground supports	0,1
	A7	Number of possible positions	0,05

Figure 2. Examples of some sketches of ladders produced by students. Idea ‘26' is a sort of elevator (only two in the whole set) activated by a rope. Idea ‘63' is based on a common ladder but is the sole mentioning the possibility to support clothes. Idea ‘86' uses an inflatable structure.

Table 5. Codification of Idea 26 (see Figure 2), according to the three evaluators.

Attribute	EV1	EV2	EV3
A1	Segmented base	Tel. mech. with pulley	Elevator
A2	Telescopic	Missing	Linear fold
A3	Three	Adjustable base	Single
A4	System material Base	Missing	Missing
A5	Missing	Telescopic mechanism	Hand
A6	One	(not present)	Adaptable clogs
A7	Pulley and platform	(not present)	Standard
A8	Segmented base	(not present)	(not present)

Table 6. Codification of Idea 63 (see Figure 2), according to the Three evaluators.

Attribute	EV1	EV2	EV3
A1	Missing	Two or more modules	Step
A2	Hinged moduli	Steps sustain other objects	Rotational fold
A3	Two	Missing	Single
A4	Rubber feet	Missing	Clothes rack
A5	Missing	Disassembly of the system into subelements	Hand
A6	Two	(not present)	Direct
A7	Rungs	(not present)	Standard
A8	Circular feet	(not present)	(not present)

Table 7. Codification of Idea 86 (see Figure 2), according to the Three evaluators.

Attribute	EV1	EV2	EV3
A1	Missing	‘Inverted V shape’	Step
A2	Inflating regulator	Missing	Deflating
A3	Two	Missing	Single
A4	PVC base	Inflatable system	Missing
A5	Missing	Inflatable system	Hand
A6	Two	(not present)	Direct
A7	Inflatable rungs	(not present)	Standard
A8	Missing	(not present)	(not present)

Figure 3. Novelty values obtained by EV1 with the two metrics. Perfect ‘zero' values indicate that the specific evaluator was unable to assess the specific idea.

Figure 4. Novelty values obtained by EV2 with the two metrics. Perfect ‘zero' values indicate that the specific evaluator was unable to assess the specific idea.

Figure 5. Novelty values obtained by EV3 with the two metrics. Perfect ‘zero' values indicate that the specific evaluator was unable to assess the specific idea.

Table 8. Individual novelty values of ideas shown in Figure 2. The values are also graphically shown in Figures 3–5.

		Idea 26	Idea 63	Idea 86
EV1	MSMN	8.31	3.74	4.34
	M^″SMN	8.48	4.79	5.89
EV2	MSMN	6.56	4.44	6.69
	M^″SMN	7.31	6.74	8.39
EV3	MSMN	5.06	4.21	2.75
	M^″SMN	5.14	5.03	2.83

Table 9. Overall assessment results for the three evaluators.

	M^″SNM – MSNM
	Mean	St. dev.	Max
EV1	1.13	0.41	1.69
EV2	1.32	1.04	5.51
EV3	0.14	0.27	2.04

Figure A1. Ladder examples provided to students by means of projected slides.

Figure A2. Same graph shown in Figure 3, where the novelty values have been obtained by using the same weight for each attribute.

Figure A3. Same graph shown in Figure 4, where the novelty values have been obtained by using the same weight for each attribute.

Figure A4. Same graph shown in Figure 5, where the novelty values obtained are calculated by using the same weight for each attribute.

Table A1. Design requirements provided to students.

Geometry	The ladder dimensions when not used, should be reduced as much as possible
	Maximum extension lenght: 4 m
	Possibility of being used on different ground conditions (slopes, stairs, etc.)
	Maximum number of possible geometric configurations
Forces	Load capacity in each condition 250 kg.
	The ladder should resist to a free fall from 2 m
Safety	Maximum stabilisation for any ground and/or wall surface
Materials	Use only fire-resistant and corrosion-resistant materials
Use	Reduce the operations needed to make the ladder operative
Ergonomics	Maximum weight of the ladder: 20 kg
	The ladder, when in the ‘not-in-use' configuration, must be easily transportable by a single person
Maintenance	Reduce as much as possible the required maintenance operations
	Eliminate or drastically reduce the need of lubricant
Production	Consider a production of 1000 ladders/year
Costs	Maximum production cost: 30€/ladder

Fiorineschi, L., F. S. Frillici, and F. Rotini. 2020b. “Subjectivity of Novelty Metrics Based on Idea Decomposition.” International Journal of Design Creativity and Innovation 8 (223–239): 1–17. doi: https://doi.org/10.1080/21650349.2020.1811775

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