TEDS Data Dictionary

The 16 Year Number Sense (Dot Task) Web Test

Contents of this page:

Introduction
Description of Test
Test Rules
Dataset Item Variables for this Test
Table of Test Items

Introduction

This page describes the Number Sense (Dot Task) test, which was included in the 16 Year twin web study.

Description of Test

In each item of this test, an image showing a number of yellow and blue dots is presented on screen for just 0.4 second (400 milliseconds). This image is then replaced by a response screen, where the twin is asked to respond by pressing a keyboard key: B if they thought there were more blue dots, or yellow if they thought there were more yellow dots. Twins are given 8 seconds in which to respond.

After responding to each item, by pressing B or Y, or after an item timeout, an intermediate screen appears. On this intermediate screen, the twin is prompted to press the keyboard's space bar when ready to continue; after a short delay of 0.25 second, the next item then appears.

The introduction to the test gives the twins an opportunity to practice a minimum of 2 items, with feedback to tell them whether they gave correct responses (no feedback is given in the main test). Twins may repeat practice items before they start the main test if they wish.

The main test consists of 150 items. Items are presented in item number order, from 1 to 150, without any branching or discontinue rules. Because of the large number of items, twins are given two opportunities to "come back later", i.e. to pause the test and resume at a later time - these opportunities appear after items 50 and 100. To avoid disrupting the flow of the test, the "come back later" option is not presented at any other times. The items are presented in full in the table below.

Because of the way the items are presented, under strict timed conditions, the test runs entirely in the twin's web browser and data are only sent back to the server after each block of 50 questions. As a result, if the test is interrupted in any way once it has started then the test ends without any data being recorded, and the test cannot be resumed or re-started. The test is then labelled as "abandoned", and no data are recorded. The twin then resumes the web battery at the next activity. Any of the following may cause the test to be abandoned, once started: twin's computer crashes; server software crashes; loss of internet connection; browser closed during test; twin clicks browser's Back or Refresh buttons.

Test Rules

Scoring
For each question, the correct response is given a score of 1, and an incorrect response or a timeout is given a score of 0. The practice items do not contribute to the total test score. The total test score is the sum of the item scores for items 1 to 150. The maximum total score for the test is 150.
Responses
Only the keyboard keys Y and B will register any response. Responses are recorded in coded form as 1=B (more blue dots), 2=Y (more yellow dots) or 3=timed out in the raw data.
Timeout rule
A timeout of 8 seconds applies to each item. After 8 seconds with no response, the item is forfeited with zero score, and the intermediate screen appears asking the twin to continue with the next item (by pressing the space bar).

Item Variables

The item variables relating to the Number Sense test, as listed in the table below, were generated automatically by programs on the web server during the course of the test. Note that the dataset only includes data for completed tests. If a twin started the test but left it unfinished, then the data for the test were not used.

In most cases the values of these variables have been left unaltered, although some have been recoded during data cleaning as follows. See the web data cleaning page for further details.

For timed out items, the item response variable is recoded from 3 to -1, and the item answer time is recoded from 8 to missing (item scores are 0)
For items that crashed or malfunctioned in any way, the item response variable is recoded from missing to -4, and the item score is recoded from missing to 0.
For twins identified as random responders in this test, the status flag is recoded from 2 to 4, the data flag is recoded from 1 to 0, and all item variables are recoded to missing (test data deleted)
For tests that were abandoned or crashed, the test status flag is recoded from 2 to 3, the data flag is recoded from 1 to 0, and all item variables are recoded to missing (test data deleted)

The test start and end dates and times, and item answer times, have not been retained in the dataset.

Variables	Explanation	Values
pcnsstat1/2	Status flag: outcome of test	0=not started, 2=successfully completed, 3=abandoned, crashed or serial timeouts, 4=random responses
pcnsdata1/2	Data flag: is test data present?	0=no, 1=yes
pcnstot1/2	Total score for this test, out of 150.	0 to 150 (integer values)
pcnsquan1/2	Number of questions answered in the test	integer values up to 150
pcnsstdt1/2	Start date of the test [not in dataset]	Date values
pcnssttm1/2	Start time of the test [not in dataset]	Time values
pcnsendt1/2	End date of the test [not in dataset]	Date values
pcnsentm1/2	End time of the test [not in dataset]	Time values
pcnstmel1/2	Total time elapsed during the test, in seconds	Integer values (number of seconds)
pcnssess1/2	Number of sessions (at the computer) used by the twin to complete the test.	Integer values of 1 or above
pcnsXXXan1/2 (XXX is the item number 001 to 150)	Item response	1=more blue, 2=more yellow, -1=timeout, -4=item crashed
pcnsXXXsc1/2 (XXX is the item number 001 to 150)	Item score	0=incorrect, 1=correct
pcnsXXXat1/2 (XXX is the item number 001 to 150	Answer time: length of time (in seconds) taken by the twin to respond to this item [not in dataset]	Decimal values, recorded to 3 decimal places (seconds, between 0 and 8)

Test Items

There are 150 items in the main part of the test. 75 of these have more yellow dots, and 75 have more blue dots. Every image is the same size, and appears in the same position on screen.

Item no.	Yellow dots	Blue dots	Correct response
1	16	5	Y
2	17	13	Y
3	14	18	B
4	7	5	Y
5	13	16	B
6	14	17	B
7	18	21	B
8	19	6	Y
9	16	13	Y
10	6	15	B
11	17	13	Y
12	12	19	B
13	20	17	Y
14	6	17	B
15	16	5	Y
16	15	19	B
17	9	11	B
18	13	10	Y
19	20	6	Y
20	17	14	Y
21	11	15	B
22	14	17	B
23	9	11	B
24	19	10	Y
25	15	13	Y
26	9	11	B
27	20	17	Y
28	5	14	B
29	7	16	B
30	19	15	Y
31	11	13	B
32	9	20	B
33	19	16	Y
34	17	12	Y
35	20	17	Y
36	11	13	B
37	10	13	B
38	7	13	B
39	21	8	Y
40	15	8	Y
41	11	9	Y
42	8	19	B
43	13	11	Y
44	21	9	Y
45	14	17	B
46	15	11	Y
47	13	15	B
48	5	9	B
49	9	11	B
50	20	17	Y
51	14	18	B
52	14	17	B
53	13	17	B
54	20	14	Y
55	17	11	Y
56	13	15	B
57	13	15	B
58	13	15	B
59	14	10	Y
60	17	21	B
61	15	19	B
62	11	9	Y
63	18	14	Y
64	10	13	B
65	13	15	B
66	17	13	Y
67	17	9	Y
68	17	14	Y
69	9	13	B
70	7	13	B
71	17	20	B
72	20	17	Y
73	5	7	B
74	19	14	Y
75	13	15	B
76	13	15	B
77	16	9	Y
78	10	7	Y
79	17	14	Y
80	16	21	B
81	13	16	B
82	8	13	B
83	21	15	Y
84	18	13	Y
85	15	13	Y
86	16	21	B
87	11	14	B
88	14	19	B
89	7	5	Y
90	20	17	Y
91	13	17	B
92	19	16	Y
93	14	17	B
94	21	17	Y
95	18	14	Y
96	19	16	Y
97	17	21	B
98	14	17	B
99	13	15	B
100	17	14	Y
101	18	11	Y
102	11	8	Y
103	17	21	B
104	14	17	B
105	6	11	B
106	19	15	Y
107	20	17	Y
108	11	17	B
109	11	13	B
110	8	14	B
111	21	17	Y
112	21	13	Y
113	14	17	B
114	16	19	B
115	20	12	Y
116	7	5	Y
117	17	14	Y
118	14	19	B
119	13	21	B
120	12	8	Y
121	19	16	Y
122	17	14	Y
123	11	14	B
124	11	13	B
125	8	11	B
126	18	14	Y
127	19	16	Y
128	10	17	B
129	13	11	Y
130	16	11	Y
131	11	15	B
132	11	13	B
133	16	19	B
134	14	11	Y
135	11	13	B
136	17	20	B
137	17	20	B
138	17	12	Y
139	19	15	Y
140	11	14	B
141	14	18	B
142	19	14	Y
143	14	11	Y
144	8	11	B
145	10	14	B
146	16	21	B
147	21	15	Y
148	20	17	Y
149	18	14	Y
150	14	18	B

Item no.	Yellow dots	Blue dots	Correct response
1	16	5	Y
2	17	13	Y
3	14	18	B
4	7	5	Y
5	13	16	B
6	14	17	B
7	18	21	B
8	19	6	Y
9	16	13	Y
10	6	15	B
11	17	13	Y
12	12	19	B
13	20	17	Y
14	6	17	B
15	16	5	Y
16	15	19	B
17	9	11	B
18	13	10	Y
19	20	6	Y
20	17	14	Y
21	11	15	B
22	14	17	B
23	9	11	B
24	19	10	Y
25	15	13	Y
26	9	11	B
27	20	17	Y
28	5	14	B
29	7	16	B
30	19	15	Y
31	11	13	B
32	9	20	B
33	19	16	Y
34	17	12	Y
35	20	17	Y
36	11	13	B
37	10	13	B
38	7	13	B
39	21	8	Y
40	15	8	Y
41	11	9	Y
42	8	19	B
43	13	11	Y
44	21	9	Y
45	14	17	B
46	15	11	Y
47	13	15	B
48	5	9	B
49	9	11	B
50	20	17	Y
51	14	18	B
52	14	17	B
53	13	17	B
54	20	14	Y
55	17	11	Y
56	13	15	B
57	13	15	B
58	13	15	B
59	14	10	Y
60	17	21	B
61	15	19	B
62	11	9	Y
63	18	14	Y
64	10	13	B
65	13	15	B
66	17	13	Y
67	17	9	Y
68	17	14	Y
69	9	13	B
70	7	13	B
71	17	20	B
72	20	17	Y
73	5	7	B
74	19	14	Y
75	13	15	B
76	13	15	B
77	16	9	Y
78	10	7	Y
79	17	14	Y
80	16	21	B
81	13	16	B
82	8	13	B
83	21	15	Y
84	18	13	Y
85	15	13	Y
86	16	21	B
87	11	14	B
88	14	19	B
89	7	5	Y
90	20	17	Y
91	13	17	B
92	19	16	Y
93	14	17	B
94	21	17	Y
95	18	14	Y
96	19	16	Y
97	17	21	B
98	14	17	B
99	13	15	B
100	17	14	Y
101	18	11	Y
102	11	8	Y
103	17	21	B
104	14	17	B
105	6	11	B
106	19	15	Y
107	20	17	Y
108	11	17	B
109	11	13	B
110	8	14	B
111	21	17	Y
112	21	13	Y
113	14	17	B
114	16	19	B
115	20	12	Y
116	7	5	Y
117	17	14	Y
118	14	19	B
119	13	21	B
120	12	8	Y
121	19	16	Y
122	17	14	Y
123	11	14	B
124	11	13	B
125	8	11	B
126	18	14	Y
127	19	16	Y
128	10	17	B
129	13	11	Y
130	16	11	Y
131	11	15	B
132	11	13	B
133	16	19	B
134	14	11	Y
135	11	13	B
136	17	20	B
137	17	20	B
138	17	12	Y
139	19	15	Y
140	11	14	B
141	14	18	B
142	19	14	Y
143	14	11	Y
144	8	11	B
145	10	14	B
146	16	21	B
147	21	15	Y
148	20	17	Y
149	18	14	Y
150	14	18	B

Item no.	Yellow dots	Blue dots	Correct response
1	16	5	Y
2	17	13	Y
3	14	18	B
4	7	5	Y
5	13	16	B
6	14	17	B
7	18	21	B
8	19	6	Y
9	16	13	Y
10	6	15	B
11	17	13	Y
12	12	19	B
13	20	17	Y
14	6	17	B
15	16	5	Y
16	15	19	B
17	9	11	B
18	13	10	Y
19	20	6	Y
20	17	14	Y
21	11	15	B
22	14	17	B
23	9	11	B
24	19	10	Y
25	15	13	Y
26	9	11	B
27	20	17	Y
28	5	14	B
29	7	16	B
30	19	15	Y
31	11	13	B
32	9	20	B
33	19	16	Y
34	17	12	Y
35	20	17	Y
36	11	13	B
37	10	13	B
38	7	13	B
39	21	8	Y
40	15	8	Y
41	11	9	Y
42	8	19	B
43	13	11	Y
44	21	9	Y
45	14	17	B
46	15	11	Y
47	13	15	B
48	5	9	B
49	9	11	B
50	20	17	Y
51	14	18	B
52	14	17	B
53	13	17	B
54	20	14	Y
55	17	11	Y
56	13	15	B
57	13	15	B
58	13	15	B
59	14	10	Y
60	17	21	B
61	15	19	B
62	11	9	Y
63	18	14	Y
64	10	13	B
65	13	15	B
66	17	13	Y
67	17	9	Y
68	17	14	Y
69	9	13	B
70	7	13	B
71	17	20	B
72	20	17	Y
73	5	7	B
74	19	14	Y
75	13	15	B
76	13	15	B
77	16	9	Y
78	10	7	Y
79	17	14	Y
80	16	21	B
81	13	16	B
82	8	13	B
83	21	15	Y
84	18	13	Y
85	15	13	Y
86	16	21	B
87	11	14	B
88	14	19	B
89	7	5	Y
90	20	17	Y
91	13	17	B
92	19	16	Y
93	14	17	B
94	21	17	Y
95	18	14	Y
96	19	16	Y
97	17	21	B
98	14	17	B
99	13	15	B
100	17	14	Y
101	18	11	Y
102	11	8	Y
103	17	21	B
104	14	17	B
105	6	11	B
106	19	15	Y
107	20	17	Y
108	11	17	B
109	11	13	B
110	8	14	B
111	21	17	Y
112	21	13	Y
113	14	17	B
114	16	19	B
115	20	12	Y
116	7	5	Y
117	17	14	Y
118	14	19	B
119	13	21	B
120	12	8	Y
121	19	16	Y
122	17	14	Y
123	11	14	B
124	11	13	B
125	8	11	B
126	18	14	Y
127	19	16	Y
128	10	17	B
129	13	11	Y
130	16	11	Y
131	11	15	B
132	11	13	B
133	16	19	B
134	14	11	Y
135	11	13	B
136	17	20	B
137	17	20	B
138	17	12	Y
139	19	15	Y
140	11	14	B
141	14	18	B
142	19	14	Y
143	14	11	Y
144	8	11	B
145	10	14	B
146	16	21	B
147	21	15	Y
148	20	17	Y
149	18	14	Y
150	14	18	B

Item no.	Yellow dots	Blue dots	Correct response
1	16	5	Y
2	17	13	Y
3	14	18	B
4	7	5	Y
5	13	16	B
6	14	17	B
7	18	21	B
8	19	6	Y
9	16	13	Y
10	6	15	B
11	17	13	Y
12	12	19	B
13	20	17	Y
14	6	17	B
15	16	5	Y
16	15	19	B
17	9	11	B
18	13	10	Y
19	20	6	Y
20	17	14	Y
21	11	15	B
22	14	17	B
23	9	11	B
24	19	10	Y
25	15	13	Y
26	9	11	B
27	20	17	Y
28	5	14	B
29	7	16	B
30	19	15	Y
31	11	13	B
32	9	20	B
33	19	16	Y
34	17	12	Y
35	20	17	Y
36	11	13	B
37	10	13	B
38	7	13	B
39	21	8	Y
40	15	8	Y
41	11	9	Y
42	8	19	B
43	13	11	Y
44	21	9	Y
45	14	17	B
46	15	11	Y
47	13	15	B
48	5	9	B
49	9	11	B
50	20	17	Y
51	14	18	B
52	14	17	B
53	13	17	B
54	20	14	Y
55	17	11	Y
56	13	15	B
57	13	15	B
58	13	15	B
59	14	10	Y
60	17	21	B
61	15	19	B
62	11	9	Y
63	18	14	Y
64	10	13	B
65	13	15	B
66	17	13	Y
67	17	9	Y
68	17	14	Y
69	9	13	B
70	7	13	B
71	17	20	B
72	20	17	Y
73	5	7	B
74	19	14	Y
75	13	15	B
76	13	15	B
77	16	9	Y
78	10	7	Y
79	17	14	Y
80	16	21	B
81	13	16	B
82	8	13	B
83	21	15	Y
84	18	13	Y
85	15	13	Y
86	16	21	B
87	11	14	B
88	14	19	B
89	7	5	Y
90	20	17	Y
91	13	17	B
92	19	16	Y
93	14	17	B
94	21	17	Y
95	18	14	Y
96	19	16	Y
97	17	21	B
98	14	17	B
99	13	15	B
100	17	14	Y
101	18	11	Y
102	11	8	Y
103	17	21	B
104	14	17	B
105	6	11	B
106	19	15	Y
107	20	17	Y
108	11	17	B
109	11	13	B
110	8	14	B
111	21	17	Y
112	21	13	Y
113	14	17	B
114	16	19	B
115	20	12	Y
116	7	5	Y
117	17	14	Y
118	14	19	B
119	13	21	B
120	12	8	Y
121	19	16	Y
122	17	14	Y
123	11	14	B
124	11	13	B
125	8	11	B
126	18	14	Y
127	19	16	Y
128	10	17	B
129	13	11	Y
130	16	11	Y
131	11	15	B
132	11	13	B
133	16	19	B
134	14	11	Y
135	11	13	B
136	17	20	B
137	17	20	B
138	17	12	Y
139	19	15	Y
140	11	14	B
141	14	18	B
142	19	14	Y
143	14	11	Y
144	8	11	B
145	10	14	B
146	16	21	B
147	21	15	Y
148	20	17	Y
149	18	14	Y
150	14	18	B