Guttman Scaling

1. Guttman Scaling

2. Guttman Scaling • Also known as • Scalogram analysis • Cumulative scaling • Purpose: • Establish a one-dimensional continuum • Perfectly predict item responses from total score • Seldom perfect in practice

3. Decide how to manage multiple tasks. 20 Decide how to manage multiple tasks. 20 Decide how to manage multiple tasks. 20 Manage resources effectively. 4 Manage resources effectively. 4 Manage resources effectively. 4 Decide how to manage multiple tasks. 20 Manage resources effectively. 4 Work quickly and effectively under pressure 49 Decide how to manage multiple tasks. 20 Work quickly and effectively under pressure 49 Work quickly and effectively under pressure 49 Decide how to manage multiple tasks. 20 Manage resources effectively. 4 Decide how to manage multiple tasks. 20 Work quickly and effectively under pressure 49 Manage resources effectively. 4 Decide how to manage multiple tasks. 20 Organize the work when directions are not specific. 39 Decide how to manage multiple tasks. 20 Decide how to manage multiple tasks. 20 Manage resources effectively. 4 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Manage resources effectively. 4 Manage resources effectively. 4 Manage resources effectively. 4 Decide how to manage multiple tasks. 20 Work quickly and effectively under pressure 49 Organize the work when directions are not specific. 39 Work quickly and effectively under pressure 49 Manage resources effectively. 4 Work quickly and effectively under pressure 49 Work quickly and effectively under pressure 49 Work quickly and effectively under pressure 49 Work quickly and effectively under pressure 49 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Work quickly and effectively under pressure 49 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Organize the work when directions are not specific. 39 Guttman Scaling Start with a large set of itemsthat you think all reflect the same construct.

4. Guttman Scaling Have many judges rate each statement with respect to whether it is favorable with respect to the construct -- a yes/norating. Rating Sheet 1 Manage time effectively 2 Manage resources effectively. 3 Scan a multitude of information and decide what is important. Yes No 4 Decide how to manage multiple tasks. Yes No 5 Organize the work when directions are not specific. Yes No Yes No 3 Scan a multitude of information and decide what is important. 1 Manage time effectively Yes No Yes No

5. Guttman Scaling Lay out a table:

6. Guttman Scaling Lay out a table: Item Item Item Item Item Item Respondent 2 7 5 3 8 ... 7 Y Y Y Y Y Y 15 Y Y Y -- Y -- 3 Y Y Y Y -- -- 29 Y Y Y Y -- -- 19 Y Y Y -- -- -- 32 Y Y -- Y -- -- 41 Y Y -- -- -- -- 6 Y Y -- -- -- -- 14 Y -- -- Y -- -- 33 -- -- -- -- -- --

7. Guttman Scaling When sorted by row and column it will show whether there is a cumulative scale. Lay out a table: Item Item Item Item Item Item Respondent 2 7 5 3 8 ... 7 Y Y Y Y Y Y 15 Y Y Y -- Y -- 3 Y Y Y Y -- -- 29 Y Y Y Y -- -- 19 Y Y Y -- -- -- 32 Y Y -- Y -- -- 41 Y Y -- -- -- -- 6 Y Y -- -- -- -- 14 Y -- -- Y -- -- 33 -- -- -- -- -- --

8. Guttman Scaling When sorted by row and column it will show whether there is a cumulative scale. Lay out a table: Item Item Item Item Item Item Respondent 2 7 5 3 8 ... 7 Y Y Y Y Y Y 15 Y Y Y -- Y -- 3 Y Y Y Y -- -- 29 Y Y Y Y -- -- 19 Y Y Y -- -- -- 32 Y Y -- Y -- -- 41 Y Y -- -- -- -- 6 Y Y -- -- -- -- 14 Y -- -- Y -- -- 33 -- -- -- -- -- -- Note the exceptions.

9. Guttman Scaling • There are several statistical techniques for examining the table to find a cumulative scale. • Because there is seldom a perfectly cumulative scale, we usually have to test how good it is. • These statistics also estimate a scale score value for each item.

10. How Does Respondent Use? • For selected items (the final scale), they simply answer whether they agree or not (yes/no). • Since each item has a scale value, we can add these values. • Total score is the sum of the scale items respondent agreed to.