ANOVA, chi square and correlation (Finals) Flashcards
What is the difference between ANOVA and the t tests?
ANOVA can be used when there are two or more means being compared, whereas the t tests are limited to situations where only two means are involved. ANOVA - 3 or more t-test - 2 only
TRUE OR FALSE: The no-preference null hypothesis will always produce equal fe values.
True
Measure differences within treatment due to
Random, unsystematic factors
TRUE or FALSE: The test statistic for ANOVA is an F-ratio, which is a ratio of three sample variances.
False, two
A research study that involves only one factor is called a ________________
single-factor design
TRUE OR FALSE: When there are large differences between fo and fe, the value of chi-square would be small.
False, large
___________________ measures the direction and degree of linear (straight line) relationship between two variables.
Pearson correlation
TRUE or FALSE: F is near 1.00 if Ho is false.
False, true
A ________ is a statistical method used to measure and describe the relationship between two variables.
correlation
When both variables are dichotomous, the resulting correlation is called a ________.
phi-coefficient
TRUE or FALSE: The purpose of ANOVA is much the same as the t tests
True
The __________________________________________ is measured by the numerical value of the correlation. A value of 1.00 indicates a perfect relationship and a value of zero indicates no relationship.
degree of relationship (the strength or consistency of the relationship)
TRUE or FALSE: Chi-square is a hypothesis testing procedure for nominal variables
True
What are the categories of Ho for Chi-square test for goodness of fit?
- No preference 2. No difference from a comparison population
The Pearson correlation requires that the scores be __________ from an ___________ scale of measurement.
numerical values interval or ratio
TRUE or FALSE: One of the assumption of parametric tests is that populations follow a normal curve
True
This is used in situations where the researcher wants to determine whether there are preferences among categories
No Preference Ho
TRUE or FALSE: A repeated-measures ANOVA eliminates the influence of individual differences from the analysis
True
What information is provided by the sign ( + or - ) of the Pearson correlation?
Direction
The frequency value that is predicted from the null hypothesis and the sample size
Expected frequency
The number of individuals from the sample who are classified in a particular category
Observed frequency
In analysis of variance an independent or a quasi-independent variable is called a _____
factor
A __________ measures the relationship between two variables (X and Y) while eliminating the influence of a third variable (Z).
partial correlation
This specifies the proportion of the population in each category
Null hypothesis
TRUE OR FALSE: The null hypothesis is used to generate a set of expected frequencies
true
TRUE OR FALSE: The typical chi square distribution is negatively skewed.
False, positively
Another strategy for non-normal distributions is to covert scores to _____
ranks
TRUE or FALSE: Non-parametric tests typically make assumptions about the shape of the distribution
False, Parametric tests
What are the two stages of the repeated ANOVA?
- Divide the variability into two components (Between and within variances) 2.individual differences are measured and subtracted out of the denominator of the F-ratio.
Non=parametric tests are sometimes called ________________
Distribution-free tests
__________ measures the portion of variability in one variable that can be predicted using the relationship with the second variable.
coefficient of determination
A study with more than one factor is called a
factorial design
TRUE or FALSE: When the null hypothesis is true and there are no differences between treatments, the F-ratio is balanced.
True
_____________ is a statistical procedure that determines the equation for the straight line that best fits a specific set of data.
Regression
TRUE or FALSE: ANOVA allows researcher to evaluate all of the mean differences in a single hypothesis test
True
A ___________ means that the two variables tend to change in the same direction
positive correlation
TRUE or FALSE: The existence of a significant treatment effect is apparent if the data produce a balanced F-ratio.
False, unbalanced
Lists number of observations for each combination of categories
Contingency Table
TRUE OR FALSE: The general goal of chi-square test for goodness of fit is to compare the observed frequency with the alternative hypothesis.
False, Null hypothesis
_____________ are used to reveal the real, underlying relationship between two variables when researchers suspect that the apparent relation may be distorted by a third variable.
Partial correlations
What are the two divisions of variability?
- Between treatment variance 2. Within treatment variance
ANOVA evaluates the ________ of the sample mean differences
significance
What level of data is used in non=parametric tests?
Nominal or ordinal
These tests are done after an ANOVA where H0 is rejected with more than two treatment conditions. The tests compare the treatments, two at a time, to test the significance of the mean differences.
Post hoc tests
3 aspects of relationship in a correlation
the direction the form the degree
The most common form of relationship is a __________________ which is measured by the ___________
straight line or linear relationship Pearson correlation.
The ____ of the relationship is measured by the sign of the correlation; either positive or negative
direction
This is used in situations where a specific population distribution is already known.
No difference hypothesis
TRUE OR FALSE: A small chi square value indicates that we should fail the null hypothesis
False, fail to reject
In chi-square tests, it is customary to present the scale of measurement as a ____________
series of boxes
The Spearman correlation is used when both variables are measured on __________
ordinal scales
It measures the relationship between two ordinal variables
Spearman correlation
TRUE or FALSE: Analysis of variance is necessary to protect researchers from excessive risk of a Type II error
False, Type I
This states that the population is divided equally among categories
No Preference Ho
It measures the consistency of direction of the relationship between two variables. The two variables must be converted to ranks before the ________ is computed.
Spearman correlation
This test determines how well the obtained sample proportions fit the population proportions specified by the null hypothesis
Chi-square test for goodness of fit
The value of __ is called the __________and determines the direction and degree to which the line is tilted.
b slope constant
The _________ formula can also be used to measure the relationship between two variables when one or both of the variables is dichotomous.
Pearson correlation
A ____________ means that the two variables tend to change in opposite directions
negative correlation
TRUE or FALSE: The goal of ANOVA is to determine whether the standard deviation that are obtained for sample data are sufficiently large to justify a conclusion that there are mean differences between the populations
False, Mean differences
TRUE or FALSE: A small treatment effect will produce a large value for the F-ratio
False, large
A ______ is one for which there are exactly two categories: for example, men/women or succeed/fail.
dichotomous variable
In situations where one variable is dichotomous and the other consists of regular numerical scores (interval or ratio scale), the resulting correlation is called a ______
point-biserial correlation.
This measures the magnitude of differences that would be expected without any treatment effects.
MSwithin
For an analysis of variance the common technique for measuring effect size is to ______________________ that is accounted for by the treatment effects.
compute the percentage of variance
What is the major distinction between the Pearson and Spearman correlations?
Spearman correlation is computed on ranks and so depicts monotonic relationships while Pearson correlation is on true values and depicts linear relationships.
What information is provided by the numerical value of the Pearson correlation?
Degree
The value of ____ is called the ______and determines the point where the line crosses the Y-axis.
a Y-intercept
Give an example of post hoc test
Scheffe test Tukey’s HSD
Measure differences between treatment due to
- Systematic treatment effects 2.Random, unsystematic factors
Parametric tests require ________ from _____________ scale
a numerical score an interval or ratioq
TRUE OR FALSE: The chi-square goodness of fit test is designed to answer questions about proportions in the population.
True
This hypothesis testing procedure uses the proportions obtained from a sample distribution to test hypothesis about the corresponding proportions.
Chi-square test
The ANOVA simply establishes that differences exist, it does not indicate exactly which treatments are different.
True
TRUE OR FALSE: A correlation between two variables should not be interpreted as implying a causal relationship.
True
TRUE OR FALSE: Non-parametric tests are not as sensitive as parametric tests. they are more likely to fail in detecting difference between two treatments
True
The differences (or variance) between means can be caused by two sources:
- Treatment Effects 2. Chance or Sampling Error
TRUE or FALSE: The hypothesis test does not necessarily provide information about the actual size of the mean differences.
True
The ideal, hypothetical sample that would be obtained if the sample proportions were in perfect agreement with the proportions specified in the null hypothesis.
Expected frequency
