Advanced Analyses weekly questions
The regression equation for predicting number of speeding tickets (Y) from information about driver age (X) is: Y = -.065(X) + 5.57 How many tickets would you predict for a 20yo?
4.27
Name an omnibus test
ANOVA
why is it important to include ID numbers
Ability to check individual sets of data identify extremes and outliers
The introduction of planned change on one or more variables, measurement on a small number of variables, and control of other variables. Which research design is described here?
An experiment
What type of data do you need for a chi-square test?
Categorical
A moderator effect is where the size of the relationship between one variable and another variable is _______________ .
Different for the values of a third variable
effect size
Effect size is (usually) expressed as a value between 0 and 1 (i.e., a probability)
examples of nominal data
Gender, hair colour , where you live
Which of the following statements about outliers is not true?
Influential cases will always show up as outliers.
An independent-samples t-test can be used to assess
It assesses differences between two groups of participants
What should Levene's test be in order to use the 'equal variance assumed' row of a t-test?
It should be non-significant (p > 0.05)
In a multiple regression, when the IVs are highly correlated (i.e., > 0.90), which assumption is likely violated:
Multicollinearity
Can a measure be valid but not reliable?
No
How many dependent variables does a 2 x 2 factorial ANOVA have?
One
What is the process through which a conceptual variable becomes a measured variable?
Operationalisation
What does the operation "Recode Into Different Variables" do to the data?
Redistributes a range of values into a new set of categories and creates a new variable
not a main reason for missing data?
The analyst ignored the data point in SPSS.
A moderator effect is indicated if which of the following explains a significant proportion of the variance in the criterion variable?
The interaction
What does the Y intercept (b0) represent?
The predicted value of Y when X = 0.
The null hypothesis in the chi-square tests states that:
The rows and columns in the table are not associated.
Assuming a linear relationship between X and Y, which of the following is true if the correlation coefficient (r) equals -0.30?
The slope (b1) is negative.
Mediation has occurred when:
The strength of the relationship between a predictor variable and an outcome variable is reduced by including another variable in the model.
Mediation has occurs when
The strength of the relationship between a predictor variable and an outcome variable is reduced by including another variable in the model.
You have found a correlation of .42 between two variables in a sample of people. Why do you need to determine whether the correlation is statistically significant?
There might be a correlation in the sample but none in the actual population.
How many F values are calculated with a 2 x 3 mixed ANOVA?
Three
What is the purpose of a multiple regression?
To predict scores on a dependent variable from scores on multiple independent variables.
why is it important to add variable names?
You may forget what the variable is output is easier to read and understand enables better communication of data and teamwork
How many variables do you need to run a chi-square test for goodness-of-fit?
You should only have one.
A moderation effect is also known as _________.
an interaction effect
what are residuals?
difference between actual value and predicted value (error in the prediction)
If the content of a test looks as though it is measuring what it is supposed to, it is said to have high ____________ .
face validity
examples of ordinal data
first, second and third place
examples of ratio data
hight and weight
kurtosis
how flat or peaked a normal distribution is positive kurtosis - large thin peak negative kurtosis - flat peak
name the two main types of one-way ANOVA
independent measures ANOVA repeated measures ANOVA
Skew
is an indication of symmetry
omnibus test
it tells us there is a significant difference but we do not know precisely between which levels
If an interaction is significant, __________.
main effects are unimportant
Previous research has suggested that higher grades (X) predict higher happiness (Y). I think, however, grades are not the real reason that happiness increases. I hypothesise that good grades (X) boost one's self-esteem (M) which, in turn, boosts one's happiness (Y). If self-esteem explains the relationship between grades and happiness, we have a ______________ relationship between X and Y?
mediated
How many dependent variables does a 2 x 2 factorial ANOVA have?
one
Equivalent-forms reliability is also known as ________________.
parallel-forms reliability
A distribution that leans to the left and has a tail far out to the right is ___________ .
positive skewness
name ONE sampling method that is a probability method?
simple random
name three types of t-tests
single-sample t-test independent-samples t-test repeated-measures t-test
examples of interval data
temperature and time
A one-way ANOVA is similar to a t-test EXCEPT __________.
that in a one-way ANOVA, the IV can have more than two levels
what is tested in Factorial ANOVA
the difference between the slopes
interactions occur when
the effect of one IV changes over levels of another IV
ANOVA is based on
the f distribution
The most appropriate statistical test for an experiment with two independent groups and the dependent variable measured on an interval scale is:
the independent-samples t-test
In hypothesis testing, a Type 2 error occurs when:
the null hypothesis is not rejected when the alternative hypothesis is true.
What are degrees of freedom?
the number of values in the final calculation of a statistic that are free to vary
t-tests are based on
the t distribution
A dummy variable is used as an independent variable in a regression model when:
the variable involved is categorical.
