Simultaneously assembly
- 1. SIMULTANEOUS ASSEMBLY PRESENTED TO : DR.NASIR PRESENTED BY: Muhammad Munsis munsifsail@gmail.com
- 2. TEST ASSEMBLY METHODS In test assembly, items are assigned to a test from an item pool. The pool contains many items with different characteristics, for example, content specification, gender orientation, average response time, word count but also psychometric features like item information, item difficulty, or discriminating power
- 3. TEST ASSEMBLY METHODS These are much more detailed and complicated then from previous method of test assembly methods. Different methods for assembling tests with item sets are generally known to people.
- 4. MODELS FOR ASSEMBLING TEST ITEMS: IRT based test assembly CRT based test assembly Matching observed score distributions
- 5. MODELS OF ASSEMBLING MULTIPLE TESTS Sequential Assembly Simultaneous Assembly Big shadow test method Optimizing bib design
- 6. SIMULTANEOUS ASSEMBLY The previous problems are absent if the tests are assembled simultaneously (that is, as a solution to a single model). This type of assembly requires a restructuring of the problem using a new type of decision variable.
- 7. METHOD 1 SIMULTANEOUS SELECTION OF ITEMS AND SETS: This method was introduced by Van der Linden(1992) The key feature of this method is that separate decision variables for the selection of items and stimuli are defined. Variables are used to model the constraints imposed on selection of item and stimuli.
- 8. Special logical constraints are added to keep the selection of items and stimuli consistent ,that is, to prevent the selection of items without selection of stimuli or the selection of stimuli without selection of items.
- 9. METHOD 2 SIMULTANEOUS SELECTION WITH PIVOT ITEM In MIP one important factor determining solution time is number of variables in the model. It is therefore advantageous to find models for test assembly problems with item sets that are based on fewer variables with results that closely approximate those for a full simultaneous approach
- 10. It is possible to reduce the number of variables by assigning one item from each item set in the bank the status of a ‘pivot item’. Formally a pivot item is an item selected for the test if and only if its stimulus is selected for the test
- 11. In practice test constructor can be asked to select as pivot items, those items that best represent their stimuli and those that would be their first choices if the test were assembled manually
- 12. METHOD 3 SELECTION OF ALL ITEMS PER SET This test assembly was presented by Luccht and Hirsch(1991) In method 2 number of decision variables was reduced by removing the stimulus variables from the model.
- 13. A more dramatic reduction is possible if the decision variables for items can be removed. This option arises when the number of items per stimulus in the bank has already met the bounds in its constraints.