OT Research II
The value of Pearson's r ranges between
-1.0 and +1.0
A week after participating in a workshop on driving safety, we asked a sample of 30 new drivers to report their frequency of texting while driving. We then compared their scores to the national norms for this behavior and found that t(29) = 2.95, p < .01, η2= .08. The chance of a Type I error is ______.
1%
Shawn examines the relationship between creativity and academic honesty and finds the coefficient of determination equals .33 or r2= -.33. This means that ______.
33% of the variability in academic honesty is accounted for by knowing its relationship with creativity
Typically we compute the ______ confidence interval.
95%
A 95% confidence interval of 2.68 < µ1- µ2 < 5.79 tells us that we can be ______.
95% confident that the mean difference from the study represents a population of mean differences falling between 2.68 and 5.79
The simplest single N design possible is
AB
Which is an appropriate measure of effect size for dependent-samples groups?
Cohen's d
Nominal data
Data which consists of names, labels, or categories.
As his class project Reggie asks 30 undergraduates to select their preference for class format (face-to-face or online). He analyses the data and finds t(28) = 5.73, p < .05, d = .40. How should he interpret his results?
He should analyze the data again by computing a different statistical test because the data are nominal.
Which of the following is true about practical significance and dependent-samples designs?
It is an interpretation of the impact of the effect in daily life.
You want to find out whether a significantly greater percentage of students at your university binge watch television series than the national percentage for binge watching. Can you compute a one-sample test on these data?
No, the data are a nominal scale and a t test requires interval or ratio data.
The statistic used to determine whether a linear relationship exists between two interval/ratio variables is the ______.
Pearson's r
the point in the research process when no new information is discovered in data analysis
Saturation
In the regression equation, b = ______.
Slope
Dependent variable
The measurable effect, outcome, or response in which the research is interested.
The single N design is best grouped with quasi-experiments. a) True b) False
True
The quality of a qualitative study may be improved by:
Use of triangulation during the data collecting
In the regression equation, a = ______.
Y-intercept
The regression equation is always represented by the formula ______.
Y¢ = bX + a
A single N design is
a quantitative design used to examine a cause and effect relationship within a single case.
Ordinal data
a type of data that refers solely to a ranking of some kind
Correlational designs can have a greater external validity than experiments because correlational designs________________________-
better represent the everyday world where we do not manipulate or control events.
The one-way ANOVA compares ______.
between-groups variance and within-groups variance
In qualitative research the way of indexing or categorizing the text in order to establish a framework of thematic ideas is known as:
coding
The statistic that describes the proportion of variability that is accounted for by knowing the relationship between two variables is the ______.
coefficient of determination
Data for a chi-square test for independence are presented in a
contingency table.
Ratio data
continuous and have a natural zero
Having participants take part in different conditions in different orders is known as ______.
counterbalancing
The analysis of a single N design typically involves
graphing data and determining patterns using visual inspection.
For the results of a one-sample t test to be significant, the computed t value must be ______.
greater than the critical t value listed in the table for our degrees of freedom (df) and p value
A method to build a theory from case study data is
grounded theory
Assumption for a one-way independent samples ANOVA include ______.
groups are independent
Nonparametric statistics are used when we
have ordinal or nominal data.
Adding additional phases in a single N design
helps to clarify the relationship between the manipulation and the dependent variable.
The matching variable you choose should be ______.
highly correlated with your dependent variable
The strength of the relationship is evident from ______ and the direction of the relationship is evident from ______ in a correlation coefficient.
how close the correlation coefficient is to the absolute value of 1.0; the sign of the coefficient
The null hypothesis for a chi-square test for independence predicts that the two variables are
independent
A correlational design _________________________
is a type of study that tests the hypothesis that variables are related.
Researchers try to ______ between-groups variance and ______ within-groups variance.
maximize; minimize
Central tendency
mean--not skewed median--too skewed mode--nominal variables
In order to compute a one-sample t test we must ______.
measure our variable on an interval or ratio scale
A regression equation allows you to ______.
more closely estimate the value of Y for a given X value
The chi-square test compares
observed frequencies with expected frequencies.
A stable baseline is important in order to
predict future behavior.
What sampling method should not be used in a qualitative research study? a. Purposeful selection b. Random selection c. Convenience sampling d. Snowball sampling
random selection
Interval data
ratings that have both order and equal intervals between values on the scale--no true zero
Which of the following involves participants serving as their own control by participating in every condition of the experiment?
repeated-measured design
If tobt = -1.98 and tcrit= 2.16, we would ______.
retain the null hypothesis
Repeated assessment is used in a single N design in order to
rule out alternative explanations for causality.
The average error between predicted Y values and the actual Y values is called ______.
standard error of the estimate
Where does the power of the dependent-groups design come from?
the decrease in random error that is created by participant characteristics
The average difference between the scores of matched pairs or the scores for the same participants across two conditions is known as ______.
the mean difference
The line of best fit represents ______.
the predicted Y values (Y¢) for each X value in the sample range
In examining test scores from the Beery VMI of children at the local elementary school compared with a national sample, the OT finds t(19) = 4.26, p < .01. She can infer that ______.
the sample consisted of 20 participants
Correlation is the statistic used to assess________________
the validity and reliability of measures.
We should not compute a regression equation if we do not find a significant correlation between two variables because ______.
there will be too much error in our predicted values
Chi-square goodness of fit assumes an expected frequency of at least 5 in each category.
true
We compute a Spearman rho when we want to correlate ______.
two variables of ordinal data
Levene's test tells us if ______.
we have violated our assumption of homogeneity of variance
independent variable
what the researcher is controlling
One reason to use a correlational design is_______________
when an experimental study would be unethical.