Where n is the number of cases in the denominator Is computed using the familiar "pq/n" formulaįor the normal approximation to the standard error of a proportion. If the sample is equivalent to a simple random sample of a population, Standard error of each percent Standard errorsįor each type of percentage (column, row, or total)Ĭan be computed and displayed for each cell Therefore, the confidence intervals calculated by the Comparison of Meansīe a little different than the confidence intervals calculated by theĬrosstabulation program for the same proportions. Notice that the calculation of confidence intervals for a proportionīy the Comparison of Means program does not use this log transformation. This is the same procedure used by Stata to calculate confidence intervals That are asymmetric - they are a little wider in the direction of 50% This conversion back and forth to logarithms results in confidence intervals The logs of the upper bound and of the lower bound are then convertedīack to percentages (by taking the antilogs) and displayed in the table cell. The result is added to the log of the percentage to obtain theĪnd it is subtracted from the log of the percentage Multiplying the log of the standard errorīy the value of Student's t appropriate to the level of confidence The user can also select 99 percent or 90 percent. Population value of the statistic is likely to fall.īy default, the level of confidence is 95 percent, but The confidence interval is the range of values within which the Of the percentage (column, row, and/or total) in each cell. That contains the upper and lower bound of the confidence interval The corresponding statistics based on the complex sample design.Ĭonfidence intervals If this option is selected, an additional Size of the SRS standard errors or confidence intervals with One reason to request SRS calculations might be to compare the Sample were a simple random sample (SRS). Nevertheless, you can specify that the standard errors,Ĭonfidence intervals, and chi-square probability values In this case, probability values are only calculated for theĪnd not for the unadjusted chi-square statistics. Unweighted N's, do not specify a weight variable.įor complex samples, standard errors and confidence intervalsĪre calculated that take the complex design into account.Īre requested, the Rao-Scott adjustment to theĬhi-square statistics are used to create F statistics. If you want to calculate percentages and statistics using only the It is important to understand that if a weight variableĪre always computed using the weighted number of cases. You can request more than one type of percentaging in a table, but
Percentaging Defines which way to make the percents add up to 100 percent: Table Display Options for Crosstabulation Cell Contents Weight variable Cases are given different relative weights. Selection filter variable(s) Some cases are included in the analysis others are excluded.
Will be generated for each combination of variables. If charts are being generated, a separate chart is also producedįor each category of the control variable. OPTIONAL variable names Column variable(s) Variable along the top of the tableĬontrol variable(s) A separate table is produced for each category of a control variable. REQUIRED variable name Row variable(s) Variable down the side of the table Select display options After specifying the names of variables, select theĪfter specifying all variables and options, select the Given in the documentation for this study.Īside from simply specifying the name of a variable, certainĪre available to change or restrict the scope of a variable. Steps to take Specify variables To specify that a certain survey question or variable is to be The univariate distribution of one variable orĪ separate table will be produced for each category SDA Frequencies and Crosstabulation Program Display a title or label for this analysis.
Display question text for the listed variables.How cases with missing data are excluded.Standard errors - (assume simple random sampling).Diagnostic output for complex standard errors.Additional statistics - complex samples.Additional statistics - simple random samples.In addition to the help specific to each program,įeatures common to all analysis programs. Online Help for Analysis Programs - SDA 4.1
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