significance test


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Related to significance test: significance level, T test

significance test

(STATISTICS) a test designed to assess whether an observed (numerical) result can have occurred by chance. The result of the test is expressed as a statistic (e.g. t-ratio, F-ratio) which can be assessed against different levels of probability. It is usual to accept a level of probability of 0.05, i.e. that there is only a 5% probability of the result having occurred by chance.

Examples of significance tests are the t-test (parametric) and the Wilcoxon (non- parametric) (see STATISTICS AND STATISTICAL ANALYSIS). These tests are designed to test for the significance of the observed difference between two groups of data. For example, in social survey work two samples may be taken, racial attitudes in cities with and without ethnic minority problems, perhaps. There may be an apparent difference (numerical) between these groups, but the groups were samples and therefore the data is subject to SAMPLING ERROR. The difference between them must therefore be tested to see if there is a statistically significant difference between them. Significance tests are designed to set up a NULL HYPOTHESIS, stating ‘no difference’, and the test result either confirms or disconfirms this.

References in periodicals archive ?
Estimate of alternative procedures to the significance test in between subjects designs with SPSS
It is well known that widely-used statistical significance tests, including the two-sample Student t test and the ANOVA F test, are derived under an assumption of homogeneity of variance.
The task force also recommends that researchers hone their theories in small pilot studies before unleashing significance tests oil larger groups, strive for simplicity in research designs, and evaluate carefully the plausibility of data generated by computer programs.
First, it points out that Besag and Clifford's (1989) theory of generalized Monte Carlo significance tests is immediately applicable to the problem of deciding how to compare an observed-occurrence matrix with a series of occurrence matrices generated from it by the step-wise random switching process.
Significance tests Die Hard: The amazing persistence of a probabilistic misconception.
Applying the significance test of the mean differences for the pair samples, the mean gets a t value of 5.
404 r=l Significance test of variables in the cointegrating vector Restrictions [[beta].
Ideally, the outcome metric (for example, reduction in costs or duration of claim) can be quantified for both the control group and the group in the program, and they can be compared through a significance test.
Preparing the prediction--once we have chosen a regression equation whose correlation coefficient value is big enough and which is adequate from the perspective of the significance test, the decision-making party (the manager) can use this equation as a basis for analysis for the prediction that he intends to make.
In EU nature conservation law, when applying the habitats assessment of the European Habitats Directive (article 6) during the significance test and the appropriate assessment, only a few strictly limited ES could be taken into consideration, thus excluding entire categories of other ES.
To ensure an even smaller chance of having a Type I error, the statistical significance test can be set at 0.