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Questions in this quiz (40)
1The main idea of a chi square test is to...
- ATest the estimated degree of fit (proportion of variance accounted for) of one variable to the other variable
- BCompare the estimated population means, to see if they vary from each other by more than chance
- CCompare estimated population variances, to see if they vary from each other by more than chance
- DTest how well the pattern of observed frequencies fits some expected patterns of frequencies
2The degrees of freedom for the chi-square test for independence is
- AThe number of categories minus one
- BThe number of columns minus one multiplied by the number of rows minus one
- CThe total number of categories levels minus one
- DThe number of people minus the number of cells
3The variance is:
- AThe sum of the squared deviations from the mean
- BThe average of the deviations from the mean
- CThe sum of the square roots of the deviations from the mean
- DThe average of the squared deviations from the mean
4The qualitative researcher:
- ASeldom approaches the task with precisely defined hypotheses to be tested
- BAttempts to make sense out of an ongoing process that cannot always be predicted in advance
- CAlternates between induction and deduction
- DMakes initial observations, develops tentative conclusions that suggest further observation and revises the conclusions
- EAll of the above
5An advantage of qualitative research is that:
- AIt enables the research to draw conclusions about the population
- BThe researcher can control the variables under study
- CSocial life can be studied in a natural setting
- DHypotheses can be rigorously tested
- EAll of the above
6The median is greater than the mean in a distribution that is:
- Asymmetrical
- Bskewed to the right
- Cnormal
- Dskewed to the left
7A chi-square test of independence would be appropriate for examining the relationship between:
- Agender (male or female) and political orientation (measured on a 5-point scale)
- Bgender (male or female) and political orientation (conservative, liberal or other)
- Ceducation (in years) and political orientation (measured on a 5-point scale)
- Deducation (in years) and political orientation (conservative, liberal or other)
8In a chi-square test for goodness of fit, the null hypothesis is that:
- AThe number of people in one category is no greater than the number of people in the other
- BThe variances of the populations of categories are the same
- CThe proportion of people over categories breaks down the same for the two populations
- DThe means of the two populations of categories are the same
9In a normal distribution, the percentage of scores between the mean and a score one standard deviation about the mean:
- ADepends upon the value of the standard deviation
- BIs always a fixed percentage
- CDepends upon the mean
- DDepends upon the shape of the distribution
10Approximately what percentage of scores in a normal distribution is to be found between two and three SD above or below the mean?
- A2%
- B5%
- C10%
- D14%
- E34%
11What does it mean when a researcher chooses the cut-off on the comparison distribution to be .01?
- AIt means that to reject the null hypothesis the result must be higher than a Z score of .01
- BIt means that to reject the null hypothesis there must be less than a 1% chance that the results would have happened by chance if the null hypothesis was true
- CIt means that if the result is larger than 0.1 (such as 0.2 or .03), it is "statistically significant"
- DIt means that the research hypothesis is definitely true if the sample's scores on the comparison distribution is less extreme than the cut-off score that corresponds to the most extreme .1% of that comparison distirbution
12With a significance level of .05, the probability of making a Type II error when the null hypothesis has been rejected is:
- AZero
- BLess than .05
- CLess than .95
- DMore than .05
- EMore than .95
13The variance of a distribution of means is calculated by:
- AMultiplying the variance of the population of individual cases by the number of participants in each sample
- BDividing the variance of the population of individual cases by the number of participants in each sample
- CSubtracting the sample's variance from the population variance
- DTaking the square-root of the variance of the population of individual cases
14The shape of a t-distribution:
- AIs normal
- BIs positively skewed
- CIs negatively skewed
- DDepends upon sample size
15In the situation where the null hypothesis is true, the distribution from which the sample is taken is:
- AThe same as the known population's distribution
- BTo the right of the original population distribution
- CTo the left of the original population distribution
- DEither to the right or left of the original distribution, depending on whether the mean of the sample is higher or lower than the mean of the original population
16For the positivist approach to research, a theory looks like:
- AA descriptive travel book or guidebook to a different society
- BA logical system of laws, axioms and propositions
- CA critique which claims that people are being misled
- DA novel or story of specific people and places
17When testing the null hypothesis for a study with a single sample with 10 scores and an unknown population variance, the cut-off score on the comparison distribution will be _________ the cut-off on the normal curve when the variance is known
- AMore extreme than
- BThe same as
- CLess extreme than
- DEither more or less extreme or the same as depending on the population variance
18What is the main difference between a Z score and a t-score?
- At scores are used when a study is analysed with a one-tailed test
- Bt scores are used when population variance is unknown
- Ct scores are used only when the sample size is greater than 30
- Dt scores are used only when inferences are made about other samples
19What represents the situation in which the null hypothesis is true?
- AThe comparison distribution
- BThe directional distribution
- CThe non-directional distribution
- DA one-tailed test
20The Z score for your sample's mean on the distribution of means is:
- Adifferent from a normal Z score because an estimated population standard deviation is used
- Bsmaller than normal due to the reduced variance in the distribution of means
- Cconceptually similar to creating a Z score from a raw score
- Dequivalent to the sample mean divided by the population variance
21Failing to determine that the researcher hypothesis is supported by the evidence of the sample, when in fact the research hypothesis is true is called:
- AType I error
- BType II error
22When estimating the population's variance from the scores in the sample, you should:
- ALook on a special table to find the estimated variance
- BProceed normally, but interpret the results with caution
- CDivide by the sum of squared deviations by N-1 instead of N
- DMultiply the sample's variance by the degrees of freedom
23If a study was conducted at the .001 significance level instead of the more usual .05, which of the following would be true?
- AA significant finding would be easier to obtain
- BThere would be a higher chance of a Type II error
- CThe results could be compared against a Z distribution (a normal curve) instead of a t distribution
- DA smaller effect size would be easier to detect
24Which of the following is part of the process of comparing a t test for independent means?
- AEach sample's standard deviation is divided by its sample size to find the standard deviation of its population's distribution of means
- BThe population variance, which is know, is used to find the variance of the two samples
- CThe population variance is estimated, then that estimate is used to find the variance of each of the distribution of means
- DAn estimate of the population mean, based on pooled sample means, is translated into a t-score and then compared to a t distribution
25The chi-square statistic is the sum, over all categories or cells, of the following calculation made within each category or cell:
- Athe difference between the squared expected frequency and the squared observed frequency
- Bthe product of the expected frequency times the total number of cases observed in all categories or cells
- Cthe squared difference between the observed and expected frequency divided by the expected frequency
- Dthe difference between observed and expected frequencies, divided by the expected frequency
26The one important assumption for the types of chi-square tests you learned about is that:
- AThe expected frequency of cases must not be larger than the observed frequency
- BThe population distributions must be negatively skewed (or at least not positively skewed)
- CEach observed case must be unrelated to all others (that is, no two scores should come from the same participant)
- DPopulations of each variable must be distributed normally
27The distribution that is always greater than 0 and positively skewed is the distribution for:
- AZ
- Bt
- Cχ2
- Dp
28To increase the power of a planned study using a t-test for independent means, you can do all of the following except:
- AUse a less stringent alpha level
- BUse better measures
- CIncrease sample size
- DUse unequal sample sizes instead of equal ones
29When conducting a t test for independent means, if the null hypothesis is rejected, you are basically saying that:
- Athe samples were drawn from populations that were actually dependent rather than independent
- Bthe variance of one sample is so much larger than the variance of the other sample that the variances of the parent populations must not have been the same after all
- Cthe mean of one sample is so far from the mean of the other sample, that the samples must come from populations with different means
- Dthe mean of one sample is statistically the same as the mean of the other sample, so they probably come from populations with equal means
30When using a t table, the degrees of freedom you should use for a t test for independent means is:
- AThe degrees of freedom for sample 1, divided by the sum of the degrees of freedom for both samples
- BThe average of the degrees of freedom for the two samples
- CThe sum of the two sample sizes, minus one
- DThe sum of the two samples' degrees of freedom
31A contingency table is a table in which:
- AThe distributions of two nominal variables are laid out so that you have the frequencies of their combinations as well as the totals
- BChi-squares for each category are displayed over each level of the predictor variable
- CZ distributions are translated into t distributions
- Dχ2 distributions are translated into t distributions
32Which of the following is not a measure of shared variability between an IV and DV:
- Ar2
- Bn2
- Cx2
- Dβ
33If you want to know if a new depression program really works, how would you test the hypothesis that it does work?
- ATry to support the hypothesis that it does work
- BTry to reject the hypothesis that it does not work
- CTry to support the hypothesis that it does not work
- DTry to reject the hypothesis that it does work
34What is one argument for using a two-tailed test even if there is a clear rationale to use a one-tailed test?
- AIf a significant result in the opposite direction occurs, it does not have to be ignored
- BA two-tailed test gives you a better chance of getting a significant result
- CTwo tailed tests are easier to perform than one-tailed tests
- DOne-tailed tests cannot be used in almost any real study
35What would be the approximate probability of selecting a random sample of 9 scores with a mean less than 42 or greater than 58 in a normally distributed population of scores with a mean of 50 and a standard deviation of 15?
- A0.8904
- B0.0254
- C0.0557
- D0.1096
36Hypothetically, a distribution of means can be constructed by:
- Ausing the sample's mean and variance divided by the population's parameters
- Brandomly estimating the population variance from the various samples, and using the sample mean in place of μ
- Crandomly taking a very large number of samples from a population, each of the same size, and making a distribution of their means
- Dcalculating the mean of all the possible samples and dividing it by the variance
37When raw scores are transformed to Z scores, then the Z scores:
- Ahave much larger values
- Bbecome more skewed
- Cbecome less skewed
- Dhave the same shape distribution as the raw scores
38In a study with 1000 participants, if an analysis yields a 2 of 30.15, what is phi equal to?
- A0.02
- B0.08
- C0.17
- D0.32
39A university lecturer is interested in measuring the relationship between overall exam scores and time spent studying. He collects data for two variables: 1) Exam scores measured out of 100, 2) Time Studying measured in minutes. What statistic would show the relationship between these two variables?
- AT score
- BZ score
- CStandard Deviation
- DPearson's r
40A university lecturer is interested in testing whether satisfaction with teaching levels of first year statistics students change over the course of the semester. To test this, the lecturer collects a random sample of 50 first-year students and the following statistics are obtained:
Beginning of the semester, M=65.93, SD=5.88.
End of the semester, M=60.64, SD=5.37.
What statistical procedure should be used, to test whether there is a significant change in mean satisfaction levels?- ADependent samples t-test
- BOne sample Z-test
- CIndependent samples t-test
- DDependent samples Z-test
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- Psychology
- Author
- Tate Rose
- Language
- English
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- History
- Created on 1 Nov 2018 · updated on 1 Nov 2018
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