null hypothesis


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Related to null hypothesis: Alternative hypothesis, Hypothesis testing, P value

null hypothesis

[′nəl hī′päth·ə·səs]
(statistics)
The hypothesis that there is no validity to the specific claim that two variations (treatments) of the same thing can be distinguished by a specific procedure.

null hypothesis

a working hypothesis which states that there will be no statistically significant difference between the EXPERIMENTAL GROUP and CONTROL GROUP.

When an experiment is set up, or observational data collected, this is designed to test a HYPOTHESIS, or theory which has been developed from previous work. This is the EXPERIMENTAL HYPOTHESIS, and it states what the expected difference is between the groups if the theory is correct. The converse hypothesis is also conventionally stated: this is the null hypothesis, that predictions from the theory are incorrect, and there is no difference between the groups in the VARIABLE investigated. See also INDEPENDENT VARIABLE, DEPENDENT VARIABLE.

References in periodicals archive ?
To observe whether the January effect strongly or weakly exists, we do a comparison of the p-values for the null hypothesis with the p-values of the reverse null hypothesis.
Similarly, the Johansen-Fisher panel co-integration test results indicate the presence of co-integration between the nine variables, where the null hypothesis of no co-integration (r = 0) can be firmly rejected at the 1% significance level.
Additionally, see Table 1, using the.001 cut-off for the p-value produces 977 erroneous rejections of the null hypothesis.
The larger the [delta], the easier to reject the null hypothesis.
Results showed that while all the fit statistics are more or less independent of test length in the null hypothesis condition, three of them--RMSD, SRMSD, and NRMSD--are dependent on sample size.
Null hypothesis number one was; "There is no significant difference of emotional intelligence of Education, Psychology, Mass Communication, Economics, International Relations, Management Sciences and Computer Sciences university teachers" Second null hypothesis was; "There is no significant difference of emotional intelligence of Social Sciences, Management Sciences and Computer Sciences university teachers".
Livezey and Chen (1983) also suggest estimating the frequency distribution for numbers of locally significant tests using Monte Carlo methods (i.e., randomly resampling the available data in a manner consistent with the global null hypothesis; e.g., Mielke et al.
For evaluating debt-GDP ratio it is assumed that there is no significant difference in the debt as percentage of GDP before and after reforms (null hypothesis); and in alternative hypothesis there is significant difference between debt as percentage of GDP before and after reforms.
South Africa reported [rho]-values of 0.1426 and 0.10 which are greater than the critical level of 0.05, thus rejecting the null hypothesis. Table 7 shows the results of the maximum eigenvalue test.
From Table III, we failed to reject the null hypothesis, i.e.