Exam 3

Question 1

Describes the sample (can be known)

Answer 1

Statistic

Question 2

Describes the population (usually can’t be known)

Answer 2

Parameter

Question 3

Allows you to make predictions from data; you take data from samples and make generalizations about a population

Answer 3

Inferential Statistics

Question 4

Simply summaries data in a meaningful way

Answer 4

Descriptive Statistics

Question 5

Taking statistics from your sample data and using it to say something about a population parameter

Answer 5

Estimating parameters

Question 6

Assumes no difference or association between the populations from which samples are drawn; to-be-tested hypothesis

Answer 6

Null Hypothesis (H0)

Question 7

Is accepted (NOT PROVEN) if evidence suggests results obtained would be unlikely if the null hypothesis were true; assumes some difference or association

Answer 7

Alternative Hypothesis (H1)

Question 8

Independent variable will have an effect on the dependent variable for the population….

Answer 8

Alternative Hypothesis (H1)

Question 9

What are the three components of writing a hypothesis?

Answer 9

1. Specificity
2. Clarity
3. Testability

Question 10

Assigning values (numbers) to objects or events based on agreed-upon rules

Answer 10

Measurement

Question 11

Obtain values from a device (ruler, visipitch, spectrograph)

Answer 11

Instrumental

Question 12

Trained individual judges quality or occurrence of events (e.g. severity ratings, stuttering frequency)

Answer 12

Observational

Question 13

T/F: A behavioral test instrument may yield observational data.

Answer 13

TRUE

Question 14

What is the order of level of measurements from weakest to strongest?

Answer 14

Nominal, ordinal, ration, and interval

Question 15

Categorical - items are assigned to different, mutually exclusive categories. Ex. religion, gender, ethnicity

Answer 15

Nominal Scale

Question 16

Ordinal, interval, and ration are all termed….

Answer 16

Continuous (things can be ordered)

Question 17

You can’t tell if the difference between times is equal from one rank to the next (ex. severity index, size, stimulus complexity, class rank)

Answer 17

Ordinal Data

Question 18

Constant distance between equal intervals on the scale is maintained (2-1 = 3-2)

Answer 18

Interval Scale

Question 19

Can identify equivalent ratio values across the scale; One thing IS twice as much as something else; a true zero point exists

Answer 19

Ratio Scale

Question 20

Indicates how likely it is that a result occurred by chance alone; measures the strength of the evidence against the null hypothesis

Answer 20

Probability value

Question 21

T/F: Smaller p-value indicates stronger evidence against the null hypothesis.

Answer 21

TRUE

Question 22

Nondirectional; null hypothesis of no difference (or association); alternative hypothesis - a difference exists

Answer 22

Two-tailed test

Question 23

Directional; alternative hypothesis - goes in only one direction; null hypothesis, no difference

Answer 23

One-tailed test

Question 24

T/F: One tailed test tends to ignore evidence in the wrong direction

Answer 24

TRUE

Question 25

T/F: Two-tailed test is more conservative (safer)

Answer 25

TRUE

Question 26

Assumes that the population measured is normally distributed (bell-shaped, not skewed, not too peaky or flat)

Answer 26

Parametric Tests

Question 27

Informally describes the degree to which the distribution is symmetrical

Answer 27

Skewness

Question 28

Informally, describes the "peakedness" and the shape of the tails of the distribution

Answer 28

Kurtosis

Question 29

Direction of the relationship

Answer 29

Sign (positive or negative)

Question 30

Degree of predictability

Answer 30

Strength

Question 31

y tend to increase when x increases is…..

Answer 31

Positive association

Question 32

y tends to decrease when x increases

Answer 32

Negative Association

Question 33

Score on x tells you nothing about what the corresponding score on y is likely to be (no positive or negative trend is visible in the plot of the paired points)

Answer 33

No association

Question 34

What tell you how much information knowing one variable gives you about the other - whether positive or negative

Answer 34

Strength of Association

Question 35

When the correlation between two variables is caused by another (third) variable, with which both are correlated

Answer 35

Third Variable Effect

Question 36

Want to know whether there is a relationship between two things - both continuous

Answer 36

Associations

Question 37

Want to know whether differences in performance can be found - across groups or tasks

Answer 37

Difference

Question 38

When are independent sample t-tests used?

Answer 38

When comparing the mean of one population to the mean of another population

Question 39

When are paired sample t-tests used?

Answer 39

When interested in the difference between two variables for the sample population

Question 40

What we really want to know

Answer 40

Population Parameters

Question 41

What we can know

Answer 41

Statistics of Samples

Question 42

P-value is less than or equal to 0.05 means...

Answer 42

Statistically significant

Question 43

P-value is greater than 0.05 means...

Answer 43

Not significant

Question 44

Two groups differ without specifying direction

Answer 44

two-tailed hypothesis

Question 45

the mean in a sample group will be less than the mean in a comparison group

Answer 45

one-tailed hypothesis

Question 46

Does positive skew lean towards the left or to the right?

Answer 46

Right

Question 47

Does negative skew lean towards the left or the right?

Answer 47

Left

Question 48

Non-parametric version of correlation; does not assume normal distribution; requires ordinal data

Answer 48

Spearman's Rho

Question 49

Parametric statistic; requires interval or ratio data; assumes a normal distribution and equal variance for each variable; range -1 to 1

Answer 49

Pearson's r

Question 50

What type of question is.... Are scores on tests of phonological awareness predictive of later reading ability?

Answer 50

Association

Question 51

What type of question is..... Do subjects perform better on a task following training?

Answer 51

Difference

Question 52

one independent variable with more than two levels

Answer 52

One-way ANOVA

Question 53

used to determine which pairs of means are significantly different from each other

Answer 53

Post-hoc Tests

Question 54

Allows the researcher to manipulate two factors at a time; two independent variables

Answer 54

Two-way ANOVA

Question 55

more than two independent variables

Answer 55

Three-way ANOVA