Part 3 of Creating Tables in Q (Video) |
Conducts tests of statistical significance for the dependent question compared with each of the independent questions. The results of these tests are added to the Report tree, ranked according to statistical significance.
To use Smart Tables, select Create > Tables > Smart Tables.
How Smart Tables works
- A significance test is conducted on each of the tables formed by crosstabbing the Dependent Question with each of the Independent Questions (see Planned Tests Of Statistical Significance).
- The results of the significance test are shown on the table name (see the example below).
- The tables are ordered according to their p-Value, with the most significant results shown at the top.
- The tables are grouped into the following categories (where applicable):
- Significant. These are tables which have a p-Value that is less than or equal to the Overall significance level (taking into account any Multiple Comparison Corrections that have been specified for the cells of the table). The p-value that equates to a corrected p-value at the specified Overall significance level is shown in brackets in name of the first Folder (e.g., Significant p <= 0.071). For more information about corrected p-value, see Multiple Comparisons (Post Hoc Testing).
- p-Value could not be computed. For example, tables where there is no variation in one of the questions.
Some general comments about Smart Tables
- Smart Tables orders results according to p-Values. While p-Values are a useful measure of the strength of association between different questions, there are sometimes better measures. Also, sometimes there will be ties, so the actual order with which things are shown should not generally be treated as a result.
- Statistical significance is not the same as causation.
- It ignores the likelihood that many of the questions are correlated. An alternative approach which resolves this problem, but introduces others, is to use Trees.
Buttons, options and fields
Dependent question The question that will be used in comparison against each of the independent questions. This comes from the question currently in the blue drop-down.
Available questions The list of all questions available to use as independent questions.
Independent questions The list of questions that will be tested for statistical significance against the dependent question.
Move the selected questions in the Available questions list to the Independent questions list.
Move the selected questions in the Independent questions list to the Available questions list.
Filter drop-downThe filter variable to apply during the significance testing.
Weight drop-down The weight variable to apply during the significance testing.
The Smart Tables output is a set of tables, appended to the Report. The tables form a part of a folder named after the dependent question (with Smart Tables affixed at the end; e.g., Q7. Company currently with: Smart Tables. Within this folder there are two sub-folders – one called Significant (p <= 0.05) which contains questions which were significantly related to the dependent question, and another showing the insignificant questions. The cut-off p-value is determined by the settings of the Overall significance level and Multiple comparisons method. Within each folder, the tables are ordered according to their p-values, with the most significant results shown at the top.