The development of categorisation and conceptual thinking in early childhood: methods and limitations

Psicologia: Reflexão e Crítica

Psychology: Research and Review

Table 2 Number of studies for each set in relation to design type, temporality, sample type and stimuli

Study set	Design type		Temporality			Sample type			Stimuli⁺
	D	E	Cs	Cq	L	CS	Int	Ext	R	O	A	NO	D/I	P	V	L	S/M
Preference and habituation	-	156	141	15	-	-	153	3	18	18	6	5	86	15	17	11	12
Category extension	1	48	37	10	2	-	46	3	12	8	18	13	3	-	3	2	-
Object sorting	-	5	3	2		-	5	-	2	3	-	3	-	-	-	2	-
Sequential touching	-	27	7	18	2	-	25	2	28	5	4	1	2	1	-	-	-
Object examining	-	34	22	11	1	-	32	2	21	2	-	13	-	-	-	4	-
Other methods	7	3	3	3	4	2	8	-	1	1	3	-	2	-	-	-	-
Total	8	273	213	59	9	2	269	10	82	37	31	35	93	16	20	19	12

Note. D= descriptive, E= experimental; Cs= cross-sectional, Cq= cross-sequential, L =longitudinal; Cs= case study; Int= intensive, Ext= extensive; R= replicas, O= objects; A= artefacts; NO= non-objects; D/I= drawings and images; P= patterns; V= videos; L= language; S/M= sounds and music. ⁺ As a single study can feature more than one type of stimuli, the sum of the number of studies for each column does not reflect the total number of studies we analysed