17.3.2.1 The Two-Sample T-Test Dialog Box

Supporting Information

To open the Two-Sample t-Test dialog box:

With a worksheet active, click Statistics: Hypothesis Testing: Two-Sample t-Test.

See Also:

Recalculate

Controls recalculation of analysis results

Indexed

The input data consists of one sample data column and one grouping column. For help with range controls, see: Specifying Your Input Data

Group Range

The grouping column. Note that the grouping column will be set as categorical if Text column.

Data Range

The sample data column.

Raw

The input data consists of two sample data columns. For help with range controls, see: Specifying Your Input Data

1st Data Range

The first sample column.

2nd Data Range

The second sample column.

Summarized Data

Summarized Data is mean, standard derivation and sample size prepared for samples

1st Data

The first summarized data.

2nd Data

The second summarized data.

Test Mean	The hypothetical mean to be tested (0 if testing equality of means).
Null Hypothesis	The null hypothesis: No difference between Mean1 and Mean2.
Alternate Hypothesis	The alternate hypothesis: Mean1 - Mean2 <> Test Mean Difference Used for two-tailed two-sample test. Mean1 and Mean2 differ. Mean1 - Mean2 > Test Mean Difference Used for an upper-tailed two-sample test. Test Mean1 is greater than Mean2. Mean1 - Mean2 < Test Mean Difference Used for a lower-tailed two-sample test. Test Mean1 is less than Mean2.
Significance Level	Specify the significance level.
Effect Size	Calculate Cohen's d value to show the effect size which is the magnitude of the difference between actual mean difference "Mean1 - Mean2" and Test Mean you specified.
Confidence Interval(s)	Compute confidence intervals for the differences of the means. For computation details, see Algorithms (Two-Sample T-Test).
Confidence Level(s) in %	Enter space-separated confidence levels. This option is only available when Confidence Interval(s) is chosen.
Equal Variance Assumed	Choose whether assume the equal variances. When the variances of the two samples are equal or when the same sizes are same, you can check this check box; when the variances are not equal or when the sample sizes are very different, please uncheck this check box to avoid the serious error.

Minimal Difference of Interest	Specify the minimum difference from the Test Mean you are interested in. Once you enter a value in this box, the Power Anlysis graph will show the minimum sample size to detect this difference in the different powers.
Actual Power	Compute the power of the test (the probability of rejecting the null hypothesis when it is false).
Significance Level	Only available when Hypothetical Power and/or Actual Power are checked. This is the significance level (alpha value) for power computation.
Hypothetical Power	Compute the power of the test at various sample sizes.
Hypothetical Sample Size(s)	Only available when Hypothetical Power is checked. Specify hypothetical sample size(s) for power computation.

Histogram	Create a histogram.
Box Chart	Create a box chart.
Arrange Plots of Same Type in One Graph	Note that for the histograms, layers will be arranged vertically. For box chart, layers will be arranged horizontally.

For help with the range controls, see: Output Results

Results Log Output	Select to output results to the Results Log.
Output Plot Data	Specify a worksheet for output of plotted data (Origin generates tabular data when plots are created).
Output Results	Specify the worksheet for output of test results.