ch 11 understanding statistics in research

Question 1

type of stats: saying what data shows
-used to present quantitative data
-helps make sense of a large amount of data
(ex: GPA)

Answer 1

descriptive stats

Question 2

3 characteristics of a single variable (in descriptive stats)

Answer 2

-distribution
-central tendency
-dispersion

Question 3

The summary of the frequency of individual values or ranges of values for a variable, can be expressed as percentages or group

Answer 3

distribution

Question 4

what is included in central tendency

Answer 4

-mean (average)
-median
-mode (most frequent)

Question 5

what is included in dispersion

Answer 5

-range
-standard deviation

Question 6

Trying to reach conclusions that extend beyond the immediate data alone

Answer 6

inferential stats

Question 7

represents the probability of an outcome as it relates to random chance;
how likely it is that a treatment group is significantly different from a control group

Answer 7

p-value (0-1)

Question 8

p-value cutoff point for showing real-
world significance

Answer 8

0.05

Question 9

inferential statistical tests for differences

Answer 9

-chi square
-t-test
-analysis of variance (ANOVA)

Question 10

type of inferential stat test used for differences:
-used with nominal
-compares observed frequencies to expected frequencies

Answer 10

chi square

Question 11

type of inferential stat test used for differences:
-assesses whether the means of two groups
are statistically different from each other
-Appropriate when you want to compare the means of two groups
(ex: systolic BP before and after Tx)

Answer 11

t-test

Question 12

type of inferential stat test used for differences:
-tests the significance of group differences between two or more groups
-only determines that there is a difference
between groups, but doesn’t tell which is different

Answer 12

ANOVA (analysis of variance)

Question 13

inferential stat tests for relationship

Answer 13

-correlation
-multiple regression

Question 14

inferential stat test for relationship:
-used with two variables to determine a
relationship/association
-does not distinguish between independent and dependent variables

Answer 14

correlation

Question 15

inferential stat test for relationship:
-used with several independent variables and one dependent variable and used for PREDICTION
-identifies the best set of predictor variables
(ex: drug use, alcohol use, child abuse, suicidal tendencies)

Answer 15

multiple regression

Question 16

type of error: occurs when the researcher rejects the null hypothesis when it is true
-results indicate that there is a significant
difference, when in reality there is not

Answer 16

type 1: false positive

Question 17

type of error: occurs when the researcher regards the null hypothesis as true but it is false
-results indicate there is no significant
difference, when in reality there is a difference

Answer 17

type 2: false negative

Question 18

-Risk of making a type I error
-The threshold/ cutoff at which statistical
significance is reached (“priori”)

Answer 18

alpha