Dear all,
I want to compute for my study the internal consistency of the measure (split-half or even-odd reliability). For this, I need to discern properly the items of the test. After reading the documentation (i.e..: Cognitive Basic Skills (Non-Verbal) Data in the Scientific Use File by Kerstin Haberkorn, Steffi Pohl). I understand that there should be for the Matrices test in G2 two sets, with 6 items each. Accoding to the naming scheme provided in this guide, the reasoning test should have the following structure: dg-cj (as per being administered in elementary school) - 2 (as being the reasoning test ) + item identifier. If you look at the kita administration, the items identifier seem to follow a logic strucutre, so that 101 would be the first item of the first set.
However, when I look in the codebook I find the following variable names:
dgcj2103_sc2g2_c DGCF (reasoning): set 1 item 1
dgcj2105_sc2g2_c DGCF (reasoning): set 1 item 2
dgcj2104_sc2g2_c DGCF (reasoning): set 1 item 3
dgci2107_c DGCF (reasoning): set 1 item 4
dgci2108_c DGCF (reasoning): set 1 item 5
dgci2109_c DGCF (reasoning): set 1 item 6
dgcj2204_sc2g2_c DGCF (reasoning): set 2 item 1
dgcj2205_sc2g2_c DGCF (reasoning): set 2 item 2
dgcj2203_sc2g2_c DGCF (reasoning): set 2 item 3
dgcj2106_sc2g2_c DGCF (reasoning): set 2 item 4
dgcj2206_sc2g2_c DGCF (reasoning): set 2 item 5
dgci2207_c DGCF (reasoning): set 2 item 6
So my questions are, are the items with the structure dgci, indeed belong to this test? which would mean, this just an inconsistency in the naming (as they should follow the structure dgcj, as they are administered in elementary school) Or do they belong to other test? If this is the case, what are the variables for the missing items? (as there should be 6 items per set, and if we remove the dgci named variables, there are 4 items missing).
And what about the order? Should I be able to trust the correspondence in the codebook between the variable name and the item id? (e.g.: dgcj2204 is indeed set 2 item 1, even if it finishes with 04)
Thanks in advance for your help! Best regards,
Patricia