Statistics

Question 1

Statistical Significance

Answer 1

• indicates results of an analysis are unlikely to be result of chance at a specified probability level
• decision: reject null hypothesis or fail to reject null hypothesis

Question 2

P Value

Answer 2

• probability that a study’s finding is due to chance
• the actual statistic
• p=.10 means 10% probability findings are due to chance

Question 3

Alpha Level

Answer 3

• significance level
• indicates threshold the investigators have selected to detect significance
• lower alpha level, less likely to be due to chance
• a=.05
• used to determine confidence level
• decided by researchers

Question 4

Relationship Between P Value and Alpha Level

Answer 4

• if p value is .10 and alpha level is at .05 then statistic indicates 10% chance differences/relationships between samples are due to chance
• so p value > alpha level set by investigators which means they fail to reject null hypothesis
• if p value < alpha level it is statistically significant and reject the null hypothesis

Question 5

Descriptive Statistics

Answer 5

• describe actual subjects encountered in study
• measures of central tendency: mean, median, mode
• measures of variability: standard deviation and coefficient of variation (SD/mean) unitless and can compare it more easily

Question 6

Inferential Statistics

Answer 6

• used to generalize, infer, findings from study to larger population from which sample is taken
• parametric or non parametric
• tests of differences or tests of relationships

Question 7

Tests of Differences

Answer 7

• compares 2 or more groups of subjects or sets of scores from sames subject
• parametric or
• nonparametric

Question 8

Tests of Relationships

Answer 8

• determine if 2 or more variables are associated with one another
• parametric
• nonparametric

Question 9

Assumptions of Parametric Statistics

Answer 9

• normal distribution
• variances in samples being compared are roughly equal, homogenous
• data are measured on interval or ration scale (sometimes ordinal)

Question 10

Nonparametric Statistics

Answer 10

• used when normality and homogeneity of variance criteria are not met
• data are measured with nominal and ordinal scales