P5130 HA 02
The data set, Inconsistency.sav, contains the following
1. Scale scores for each of the Big Five dimensions from the “original” 50-item IPIP Big 5 questionnaire–
eorig50, aorig50, corig50, sorig50, and oorig50.
2. Scores representing inconsistency of responses to items within each of the Big Five dimensions from the
same “original” 50-item IPIP Big Five questionnaire- sdeorig50, sdaorig50, sdcorig50, sdsorig50, and
sdoorig50.
3. Scale scores for each of the Big Five dimensions from a Big Five questionnaire called the Thompson Minimarkers – emmark, ammark, cmmark, smmark, and ommark.
4. Scores representing inconsistency of responses to items within each of the Big Five dimensions from the
same Mini-markers questionnaire – sdemmark, sdammark, sdcmmarek, sdsmmark, and sdommark.
Consider the IPIP questionnaire to be the standard. This assignment involves evaluation of the convergent
and discriminant validity of the Mini-marker questionnaire scores.
1. Evaluate and report the convergent validity of each of the Mini-marker scale score variables against the
corresponding IPIP scale – E to E, A to A, etc.
2. Evaluate and report the discriminant validity of each of the Mini-marker scale score variables against the
“other” Big 5 IPIP variables. For example Mini-marker E should not correlate with IPIP A or C or S or O. Minimarker A should not correlate with IPIP E or C or S or O. Mini-marker C should not correlate with IPIP E or A or
S or O. And so forth.
3. Compute an overall Mini-marker Inconsistency scale as the mean of the 5 individual dimension
inconsistency values. Call it SDmmark.
For each row in the data editor,
sdmmark = (sdemmark + sdammark + sdcmmark + sdsmmark + sdommark)/5.
This can be done using the Transform -> compute menu.
Report the mean and standard deviation of this new variable.
4. Compute and report the reliability of the sdmmark variable. Report it, along with the RELIABILITY Table
containing “Alphas if items deleted”. The “items” are sdemmark, sdammark, sdcmmark, sdsmmark, and
sdommark.
5. Compute and report the convergent validity of sdmmark with sdorig50, the mean of the inconsistency
values from the IPIP questionnaire which has already been computed and is in the file.
6. Evaluate and report the discriminant validity of the sdmmark variable against the individual Mini-marker
scale scores – emmark, ammark, cmmark, smmark, and ommark.
For each of the above, present a table or other easy-to-follow report with appropriate correlations and a 1-2
sentence summary of the results.
Present Parts 1 – 6 in the order 1 -> 2 -> 3 -> 4 -> 5 -> 6, each part clearly labeled.
Over for a rationale for this assignment
This assignment mostly concerns a construct we are attempting to measure that we call inconsistency. We are
measuring it as the standard deviation of responses to individual items from a single Big Five dimension.
Since a Big Five questionnaire has 5 dimensions, we will get five inconsistency values for each person from
administration of a Big Five questionnaire. Computing the average of the five values gives the overall
inconsistency of responses to the questionnaire.
We are trying to determine whether it is a useful measure or not.
We are also investigating the usefulness of an alternative Big Five questionnaire called the Thompson Minimarkers. We want to know whether this questionnaire (which is shorter than the IPIP questionnaire that we
usually employ) can be a viable substitute for the IPIP questionnaire.
This assignment asks you to assess construct validity of the inconsistency measure and construct validity of
measures obtained from the Mini-marker questionnaire.