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One sample T test and Binomial
Binomial Test Options (One-Sample Nonparametric Tests)
The binomial test is intended for flag fields (categorical fields with only two categories), but is applied to all fields by using rules for defining “success”.
What it does: The One-Sample T Test compares the mean score of a sample to a known value. Usually, the known value is a population mean. ∞
Binomial or T Test
To select the right test, ask yourself two questions: What kind of data have you collected? What is your goal? Then refer to Table 37.1.
Type of Data | ||||
Goal | Measurement (from Gaussian Population) | Rank, Score, or Measurement (from Non- Gaussian Population) | Binomial (Two Possible Outcomes) |
Survival Time |
Describe one group | Mean, SD | Median, interquartile range | Proportion | Kaplan Meier survival curve |
Compare one group to a hypothetical value | One-sample ttest | Wilcoxon test | Chi-square or Binomial test ** |
|
Compare two unpaired groups | Unpaired t test | Mann-Whitney test | Fisher’s test (chi-square for large samples) |
Log-rank test or Mantel-Haenszel* |
Compare two paired groups | Paired t test | Wilcoxon test | McNemar’s test | Conditional proportional hazards regression* |
Compare three or more unmatched groups | One-way ANOVA | Kruskal-Wallis test | Chi-square test | Cox proportional hazard regression** |
Compare three or more matched groups | Repeated-measures ANOVA | Friedman test | Cochrane Q** | Conditional proportional hazards regression** |
Quantify association between two variables | Pearson correlation | Spearman correlation | Contingency coefficients** | |
Predict value from another measured variable | Simple linear regression or Nonlinear regression |
Nonparametric regression** | Simple logistic regression* | Cox proportional hazard regression* |
Predict value from several measured or binomial variables | Multiple linear regression* or Multiple nonlinear regression** |
Multiple logistic regression* | Cox proportional hazard regression* |
Z Score
How many standard deviations from the mean translates to what is the z score…
longhand version.
score / SD =
mean / SD =
Mean – Score = z score
or
score – mean =
answer / SD = Z score
It is also possible to calculate how many standard deviations 1.85 is from the mean
How far is 1.85 from the mean?
It is 1.85 – 1.4 = 0.45m from the mean
How many standard deviations is that? The standard deviation is 0.15m, so:
0.45m / 0.15m = 3 standard deviations
this is called standadising
Z-Scores
To obtain Z-scores, go to the Analyze menu, choose Descriptive Statistics, then Descriptives. Move the variable(s) for which you would like to create Z-scores into the Variables box. In the example below, we used the variable called “rosen.” Before you click OK, be sure that the box marked “Save Standardized Values as Variables” is checked.
Referencing
Referencing
confidence interval
<a href=” ” title=”confidence interval”>confidence interval
Summarising Data
Week 2