Raven's Progressive Matrices

Description of Test

This is the same version of the Ravens Matrices test that was used in the 14 Year study.

This test consists of a series of incomplete patterns ("matrices"); in each case, the twin is asked to identify the missing part of the pattern. The twin does this by clicking on one of 8 possible missing parts. The patterns and missing parts are shown in full in the table of test items below.

The test is divided into 4 sub-tests or sections, labelled C, D, E and F. Sub-tests C, D and E each consist of 6 items, numbered 1, 3, 5, 7, 9 and 11 (even-numbered items from the original version of the test were dropped); sub-test F consists of all 12 original items (numbered 1 to 12). Hence there are 30 items in total. A twin may be presented with fewer than 30 items, because of the discontinue rule (described below). The sub-tests are presented in sequence (C then D then E then F). The discontinue rule applies independently within each sub-test, as described below.

Test Rules

· Scoring

For each question, the correct response is given a score of 1, and any of the 7 incorrect responses is given a score of 0. Any question omitted due to the discontinue rule is given a score of 0. The maximum total score for the test is 30.

· Ordering of items

The 4 sub-tests are presented in sequence: C then D then E then F. Within each sub-test, items are presented in increasing numerical order of item number, subject to the discontinue rule below.

· Discontinue rule

§ Start with the first three items in the sub-test

§ (items 1, 3 and 5 for sub-tests C, D and E; items 1, 2 and 3 for sub-test F)

§ If the first three items are all incorrect, discontinue the sub-test (skip the remaining items). Move on to the next sub-test (or if in sub-test F, end the test).

§ If at least one of the first three items is correct, proceed with the remaining items of the sub-test, in numeric order. Then move on to the next sub-test (or if in sub-test F, end the test).

· Timeout rule

A nominal timeout of 5 minutes (300 seconds) applies to each item of this test. After 5 minutes with no response, the twin is automatically taken back to the menu/activity screen. However, the timed out item is not forfeited: on resuming the test, the same item is presented again to the twin. Hence there are no timed out items in the data for this test.

Item Variables

The item variables relating to the Raven's 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 successfully completed tests. If a twin started the test but left it unfinished, then the data for the test were not used. For twins identified as random responders in this test, all test data were deleted.

In most cases the values of these variables have been left unaltered, although some have been recoded during data cleaning:

For items skipped due to the discontinue rule, the item response variable is recoded from missing to -2, and the item score is recoded from missing to 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)

Variables	Explanation	Values
pcrvstat1/2	Status flag: outcome of test	0=not started, 1=started but not finished, 2=successfully completed, 4=random responses
pcrvdata1/2	Data flag: is test data present?	0=no, 1=yes
pcrvtot1/2	Total score for this test, out of 30.	0 to 30 (integer values)
pcrvquan1/2	Number of questions answered in the test	12 to 30 (integer values)
pcrvstdt1/2	Start date of the test	Date values
pcrvsttm1/2	Start time of the test	Time values
pcrvendt1/2	End date of the test	Date values
pcrventm1/2	End time of the test	Time values
pcrvsess1/2	Number of sessions (at the computer) used by the twin to complete the test.	Integer values of 1 or above
pcrvtmel1/2	Total time elapsed during the test, in seconds	Integer values (number of seconds)
pcrvXYYan1/2 where X is the sub-test (c, d, e or f), and YY is the item number within the sub-test (01 to 12, odd numbers only for sub-tests c, d and e).	Item response (picture number selected, as tabulated below)	1 to 8 (integer values), or -2=discontinued, -4=item crashed
pcrvXYYsc1/2 wwhere X is the sub-test (c, d, e or f), and YY is the item number within the sub-test (01 to 12, odd numbers only for sub-tests c, d and e).	Item score (see table of items below for details)	0=incorrect, 1=correct
pcrvXYYat1/2 where X is the sub-test (c, d, e or f), and YY is the item number within the sub-test (01 to 12, odd numbers only for sub-tests c, d and e).	Answer time: length of time (in seconds) taken by the twin to respond to this item	Integer values (number of seconds)
pcrvXYYdt1/2 where X is the sub-test (c, d, e or f), and YY is the item number within the sub-test (01 to 12, odd numbers only for sub-tests c, d and e).	Download time: length of time (in seconds) between the end of the previous item and the start of this item; time needed to download files for this item	Integer values (number of seconds)
pcrvXYYor1/2 where X is the sub-test (c, d, e or f), and YY is the item number within the sub-test (01 to 12, odd numbers only for sub-tests c, d and e).	Order or sequence of this item in the test; dependent on the discontinue rule in each sub-test	Integer values (1 to 30)

Test Items

The numbering of the items, shown in the table below, equates to the numbering used in the item variables. The order in which items are presented in this table is the same as the order in which items are presented to the twins in the test, subject to the discontinue rule (see test rules above).