Stats1 Flashcards
In ANOVA, MS provides a measure of
Variance
A hypothesis test is
Inferential technique
From sample to population
Know how to differentiate independent vs. dependent variable in a study
Birth order and personality
For goodness of fit, the null hypothesis is used to create an ideal hypothetical sample. The F in the ideal sample are called:
Expected frequencies
Independent measures study obtain :
1 group of scores for each subject
Statistical methods used to answer general questions about the population is:
Inferential statistics
By definition, a type 1 error is:
Rejecting a true Ho
Study on increased lighting and lower depression scores - what is dependent variable?
Level of depression
If random samples, each with n=9, are selected from a normal population with u=80 and @=18 and the mean is calculated for each sample, then the average distance between M and u would be?
??????
Answer is looking for standard error of the mean
Which is the following will increase power of statistical test?
Increasing sample size
“A pharmacological company has developed a drug expected to reduce hunger…”
Divide MSb/MSw
If u are asked to calculate MS remember that it is SS/df
A research uses hypothesis test to evaluate (question looking at what will give us the most power)
Smaller standard deviation and bigger sample size
Identify the symbol for population variance
@
A population mean of 85 and SD of 12 is transformed into z scores. After the transformation the population of z scores will have a SD of :
1.0
Because the transforming into z-scores resets mean back to 0 with its SD’s of 1
s =
SD=
.s = sample variance
SD = square root of variance
For a population N=10 scores, first measure the distance between each score and the mean, then square each distance and find the sun squared distance. At this point you have calculated :
SS
A high school counselor would like to know whether there is a relationship between mathematical skill and verbal skill. A sample of N=25 is selected, and the counselor records achievement test scores in mathematics and English for each student. What is the appropriate statistical procedure for this study?
Correlation
For the above table, the proportion associated with x=2 is:
X. F 5 2 4 2 3 8 2 4 1 4
0.20
The null hypothesis for chi-squared goodness of fit specifies :
Proportions for the entire population
A sample n=5 scores has M=20 and s2=4. What is the sample standard deviation?
2
Even if a treatment has no effect, it is still possible to obtain an extreme sample mean that is very different from the population mean. If this happens you are likely to :
Reject Ho and make a type 1 error
A Chinese physician wants to see if a traditional Chinese herb improves memory for elderly people. He recruited a group of participants, prescribed a placebo for a week, and measures the participants performance on a memory test at the end of the week. The next week, he prescribed the herb again and measured participants memory test at the end of the week. Participants performance on memory test is measured on a continuous scale. What statistical procedure would be most appropriate ?
Repeated measured (matched-samples) t-test
The purpose of a post-hoc test is:
To determine whether or not a Type 1 error was committed
The standard deviation of the distribution of sample means is called:
The sample mean
The chi-square test for independence is used to test for:
A relationship between two variables
The local school district is comparing two methods for teaching math to 3rd grade students. One class was taught by method A and another class was taught by method B. At the end of the school year, all of the students took a standardized achievement test. The scores for the students taught by method A produced a mean of M=75 and the students taught by method B had a mean of M=87. What is the appropriate statistic to use to analyze this data?
Independent samples t-test
In a population of =60, a score of x=58 corresponds to a z-score of -0.50. What is the population deviation?
4
Under what circumstances is the experiment wise alpha level a concern?
Whenever an experiment involves more than one hypothesis test
The distribution of sample means (for a specific sample size) consists of:
The sample means for all the possible samples (for the specific size)
Even a very small treatment effect can be statistically significant if:
The sample size is big and the population variance is small
What proportion of a normal distribution is located in the tail beyond a z-score of z= -0.50?
0.3085
A researcher uses an analysis of variance to test for mean differences among three treatment conditions using a sample of n=10 subjects in each treatment. The F-ratio from this analysis would have :
Df = 2, 27
The results of an independent-measures research study Are reported as “t(5) = -2.12, p > .05, two tails”. What statistical decision would be made ?
The researcher failed to reject Ho
For which of the following situations would a repeated-measures research design be appropriate?
Comparing pain tolerance before and after taking a new pain mes
Gender differences in dream content are well documented. Suppose a researcher studies aggression content in the dreams of men and women. Each participant reports his or her most recent dream. Then, each dream is judged by a panel of experts to have low, medium, or high aggression content. What would be the appropriate statistical test for this study ?
Chi-squared test for goodness of fit
You are entering religion data from participants in your study into SPSS, what measure should you list this data as?
Nominal
In analysis of variance, the term factor refers to:
An independent variable
The probability of committing a Type 1 error:
Is determined by the level of significant (alpha) that one chooses
What is required by the homogeneity of variance assumption?
The two population variances are equal
If treatment has a very small effect, then a hypothesis test evaluating the treatment effect is likely to:
Result in a type 2 error
an independent measures study:
Uses a different sample for each of the different treatment conditions being compared
A scatter plot shows a set of data points that are clustered close to a line that slopes down to the right. Which of the following values would be closest to the correlation for these data?
-0.80
Which of the following would have the largest value for sample variance ?
All samples would have same variance
A college professor reports that students who finish exams early tend to get better grades then students who hold on to exams until the last possible moment. The correlation between exam score and amount of time spends on the exam is an example of:
Negative correlation
Which of the following is a characteristic of a nonparametric test ?
Negative correlation
If a repeated-measures study shows a significant difference between two-treatments with alpha =.01, then you can be sure that:
A significant effect does not necessarily mean that the effect size will be large
Repeated measures study obtains :
2 scores for each subject
