Sampling, Article Review, and Scales of Measurement

1. Define a Population.

2. Define a Sample.

3. Provide an example of a research scenario and then discuss the Population and the Sample in the context of the scenario (2-3 sentences).

4. Define Bias in the context of research.

5. Indentify and define the four levels of measurement.

Part 2

Retrieve and read the guide entitled Overview Sampling Procedures published by the division of System Managements for Human Services from Fairfax Co., VA, available in this website .

Use the information provided in the publication to complete the following table:

Sampling Procedures	Sampling Type Probability Sampling or Nonprobability Sampling	Definition	Characteristics of the methodology	Limitations of the methodology	Create a short scenario where you would employ the sampling procedure
Convenience Sampling
Quota Sampling
Judgmental Sampling
Simple Random Sampling
Stratified Random Sampling
Cluster Sampling
Systematic Sampling

Part 3

Choose 1 (one) recent article from a peer-reviewed journal and answer the following questions:

Sampling Procedures

· Describe the characteristics of the population studied.

· Identify sampling procedures (e.g., simple random sampling), and explain why it was selected. Indicate the size of the sample.

· Was a probability sampling method used? Was it representative of the population?

· What was the response/participation rate? How did those who responded or participated differ from those who did not? How was this addressed?

Data Analysis

· What statistical analysis was conducted?

· What were the units of analysis (e.g., individual, group, or program)?

· What was the level of measurement for the data?

· Was the information presented in the figures and tables clear and was it discussed in the text?

Findings

· What were the study findings? Were they discussed and described clearly and accurately?

· Were explanations proposed for any anticipated and unanticipated findings?

· Were the results substantively important?

· Were conclusions well-grounded in the findings?

· Was the study conducted in an objective fashion? Is there any evidence of bias?

Your paper should include your name and course title and should adhere to APA style. It should also be written in 12-font and double-spaced (about 2 pages). Include the full reference of the article you reviewed at the end of your document.

Assignment 1: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	Basic Terminology	5	4	0-3
Part 2.	Sampling Procedures	5	4	0-3
Part 3.	Article Review	5	4	0-3
Total Points Earned: ____ / 15 Points Possible

Assignment 2: Descriptive Statistics

Part 1

Use the autoaccidents.sav file to answer the following questions and run the analysis:

What is the level of measurement for the following variables?

1. Gender

2. Age

3. Accident

Report the mean, the median, the number of cases, the range, and the standard deviation of accidents for:

1. Males.

2. Females.

3. Appropriately report the sample size (overall and subset), the standard deviation, and the mean and discuss in one paragraph the meaning of the data.

Part 2

This data set represents the average salary from 50 states coded by Alphabet. Open the dataset to run the analysis.

Salary	State		Salary	State
28659.0	A		28200.0	Z
47902.0	B		29564.0	AA
31825.0	C		37181.0	BB
28312.0	D		34121.0	CC
40636.0	E		45582.0	DD
33826.0	F		27922.0	EE
50389.0	G		45772.0	FF
37469.0	H		29727.0	GG
43014.0	I		25506.0	HH
29214.0	J		35912.0	II
36564.0	K		27612.0	JJ
27756.0	L		37589.0	KK
39416.0	M		42411.0	LL
35741.0	N		39261.0	MM
30760.0	O		29414.0	NN
31700.0	P		25259.0	OO
31369.0	Q		30514.0	PP
26243.0	R		30519.0	QQ
30996.0	S		28056.0	RR
39475.0	T		34517.0	SS
38960.0	U		33472.0	TT
45218.0	V		35860.0	UU
36146.0	W		30549.0	VV
25153.0	X		36644.0	XX
30324.0	Y		30954.0	YY

1. What is the level of measurement for Individual and for Salary?

2. Report the mean, the median, the mode, and the standard deviation.

3. Explain what the standard deviation means in the context of all the data.

4. Create a histogram of the salary distribution and use the normal curve option to illustrate your discussion.

Write up the results, using APA style, of the descriptive statistics reported for the average salary in all fifty states. Also briefly discuss the salary histogram.

Assignment 2: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	Auto Accident Analyses	5	4	0-3
Part 2.	State Salary Analyses	10	8-9	0-7
Total Points Earned: ____ / 15 Points Possible

Assignment 3: Correlations

Part 1

Answer the following questions:

1. What is the definition of a correlation and why would a researcher be interested in using this type of analysis?

2. What is another name for a Positive relationship and a Negative relationship?

3. Describe the association between two variables when the relationship is Negative.

4. Is a correlation a good way to determine cause-and-effect? Why or why not?

5. What is the coefficient of determination, give an example and describe?

Part 2

Conduct a correlational analysis on the following example:

Example: A school psychologist is interested in determining if test anxiety is affecting her students’ performance on their exams. She randomly selected 103 students from her school and conducted a correlational analysis to try and answer her question. She hypothesized that as anxiety increases, test performance decreases.

Based on this example answer the following questions:

1. Why is a correlational analysis the most appropriate technique to test her hypothesis?

2. Use the data set provided and conduct a Bivariate Correlational Analysis using SPSS.

Hint: In the Bivariate Correlations dialogue box in SPSS, select Pearson. Create a Simple Scatterplot with Exam Performance on the Y-axis and Exam Anxiety on the X-axis.

3. Observe and briefly explain the trend seen in the Scatterplot (1-3 sentences).

4. What is the strength and direction of the relationship between Performance and Anxiety?

5. Based on these findings, can she infer that one variable causes the other (i.e., cause-and-effect)? Why or why not?

6. Discuss the findings in a paragraph with APA style.

Part 3

Provide examples of the following using variables and a made-up correlation to illustrate your point:

1. Strong positive (direct) correlation.

2. Weak positive correlation.

3. Strong negative (inverse) correlation.

4. Weak negative correlation.

5. Please discuss the subjective nature of the strength of correlations you chose above. Are there and “hard and fast rules” (see Huck) in making these determinations?

Assignment 3: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	Correlation Terminology	5	4	0-3
Part 2.	Test Anxiety Analyses	5	4	0-3
Part 3.	Relationships Between Variables	5	4	0-3
Total Points Earned: ____ / 15 Points Possible

Assignment 4: t Tests

Part 1

The one sample t Test for a mean

A market research company found that children in America between the ages of 5 and 12 years old watch on average 196 minutes of TV per day. A survey was conducted by randomly selecting 20 British children within this age group to see if British children are statistically different in the amount of TV watched per night from their American counterparts.

Based on this example answer the following questions:

1. Why is a one sample t Test the most appropriate technique to test the example?

2. State (in words) the null and the alternate hypothesis.

3. Use the data set provided and conduct a one sample t Test using SPSS.

Hint: Once you are in the One Sample t Test dialogue box in SPSS, your test value will be 196 (minutes).

4. What is the Mean number of minutes watched per night?

5. What is the t statistic?

6. What is the p value or significance?

7. Discuss the findings in regard to the null and alternate hypothesis using APA style.

Part 2

The independent samples t test for the equality of Means

A survey was conducted by randomly selecting 20 American children and 20 British children to determine if there is a statistical difference in amount of time they watch TV.

Based on this example answer the following questions:

1. Why is a two samples t test most appropriate technique for this research example?

2. State (in words) the null and the alternate hypothesis.

3. Use the data set provided and conduct a two samples t test using SPSS. Use the SPSS command/actions listed below to conduct the analysis:

a. Hint: Once you are in the Independent-Samples t Test dialog box in SPSS, you will have to Define your groups.

b. Click on Define Groups

c. In the area next to Group 1: type 1, and in the next to Group 2: type 2

d. Click on Continue

e. Click on OK

4. What is the mean number of minutes of TV watched by the British children?

5. What is the mean number of minutes of TV watched by the American children?

6. In the Equal Variances Assumed row, what is the t statistic?

7. What is the p value or significance?

8. Discuss the findings in regard to the null and alternate hypothesis using APA style.

9. Why might these results be inaccurate due to the technique of Random Sampling?

Part 3

Calculate the Effect size (Cohen’s d) for the paired samples t test output:

Use the following equation: d = M1 – M2/ σ D (Mean of Post-total Social Competency – Mean of Pre-total Social Competency)/Paired Differences Std. Deviation

Cohen (1988) defined effect sizes as “small, d = .2,” “medium, d = .5,” and “large, d = .8″, stating that “there is a certain risk in inherent in offering conventional operational definitions for those terms for use in power analysis in as diverse a field of inquiry as behavioral science” (p. 25).

Discuss the meaning of the findings (1-2 sentences).

Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.).

Hillsdale, NJ: Lawrence Earlbaum Associates.

Assignment 4: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	One Sample t Test	5	4	0-3
Part 2.	Independent Sample t Test	5	4	0-3
Part 3.	Effect Size	5	4	0-3
Total Points Earned: ____ / 15 Points Possible

Assignment 5: ANOVA

Part 1

Open the divorce.sav data file and run the one-way ANOVA to answer the following question:

What are the effects of marital status on life satisfaction?

1. State the independent and dependent variables.

2. State the null and alternate hypotheses.

3. Run the appropriate analysis using SPSS (Hint: Use the General Linear Models and Univariate Procedure. Select Estimates of Effect Size under the Options tab).

4. What are the mean and standard deviation for each of the levels of the IV?

5. Report the appropriate F statistic, degrees of freedom, p value, and eta squared (η2).

6. What is your decision regarding the null hypothesis (i.e., did you reject or fail to reject the null)? Explain your decision (1 sentence)

7. Write up a sample results section using APA style.

Part 2

Use the goggles.sav data to run a two-way ANOVA. Consider the following example and then answer the subsequent questions:

Derived from Field (2005), an anthropologist was interested in the effects of alcohol on mate selection at night-clubs. Her rationale was that after alcohol had been consumed, subjective perception of physical attractiveness would become more inaccurate. She was also interested in whether this effect was different for men and women. She picked 48 students: 24 male and 24 female. She then took groups of eight participants to a night-club and gave them either a non-alcoholic lager, 2 pints of strong lager, or 4 pints of strong lager. At the end of the evening she took a photograph of the person that the participant was chatting up. She then got a pool of independent judges to assess the attractiveness of the person in each photograph (out of 100).

1. State the independent variables and the dependent variable.

2. State the null and alternate hypotheses.

3. Run the appropriate analysis and include the Levene’s (Homogeneity of Variance) test and the test of Between-Subjects Effects (Cut and Paste Levene’s Test Output Below – Explain the meaning of this test).

Tests of Between-Subjects Effects (Include Data from Output in the Figure Provided Below)

Source	Df	Mean Square	F	Sig.
Gender
Alcohol
Gender*alcohol

4. Report the mean and standard deviation for each level of the IV (Cut and Paste Output).

5. What is your decision concerning the null hypothesis (i.e., did you reject or fail to reject the null)? Explain your response.

6. Post the Estimated Marginal Means of Attractiveness of Data.

7. Using APA style, write up a sample results section.

Assignment 5: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	One-Way ANOVA	5	4	0-3
Part 2.	Two-Way ANOVA	10	8-9	0-7
Total Points Earned: ____ / 15 Points Possible

Assignment 6: Non-Parametrics

Part 1

Chi-Square Test of Association (Independence)

A school system is concerned about the low graduation rate among their high school students. The superintendent assigned a task force to research possible reasons that could explain the low graduation rate. The task force decided to conduct a preliminary literature review about current graduation rate research. The literature review signaled that among several key factors that are related to completion of high school is the development and execution of a school guidance intervention plan. The task force decided to investigate if such is the case in the high school with the highest dropout rate in their district. The following data was collected:

Valenti High School Data

	Guidance Intervention Plan
Students obtaining a high school diploma	No	Yes
No	577	46
Yes	381	492

In order to run the chi-square test of association (aka, chi-square test of independence), open the file named: assign 6 prob 1 data.sav

· Under View > Value labels you can toggle between the variable category label (no, yes) or the dummy codes (numeric representation) for the category label (0 = no, 1 = yes)

· Make sure you review both the “Data view” and “Variable view” so you understand the variable types and other properties – and how the variables were created and entered.

· Go to Analyze > Descriptive statistics > Frequencies, and move the two variables to the “Variables” box, then click “ok”

· This gives you the frequencies and percents of each of the variables

· To run the chi-square of association test, go to Analyze > Descriptive statistics > Crosstabs, then move High School Diploma (HSD) to the “Row” box, and Guidance Intervention Plan (GIP) to the “Column” box

· Select “Statistics” then select the “Chi square” and “Phi and Cramer’s V” boxes

· Click “Continue”

· Select “Cells” then select “Observed” and “Expected” under “Counts” (“Round cell counts” is selected by default)

· Click “Continue” then “ok”

Use the output for Questions 1-3:

You were asked to analyze the data and present the findings in the upcoming school board meeting. Your report must include the following:

1. A short explanation about the following (cut and past the output into your Word document):

a. Chi-Square Test of Association.

b. The Case Processing Summary table .

c. Cross tabulation table .

d. Chi-square Tests table.

e. Clustered Bar Chart.

2. Write down the value of the Pearson chi-square and its associated tail probability (p-value). Is it significant? (complete an APA style write-up)

3. In terms of the experimental hypothesis, what has this test shown?

Part 2

Chi-Square Goodness of Fit Test

Following are the cumulative number of AIDS cases reported for Neptune County through December 31, 2008, broken down by ethnicity:

Ethnicity	Actual Number of AIDS Cases
White	751
Hispanic	225
African-American	100
Asian, Pacific Islander	36
Native American	5
	Total = 1117

Ethnicity	Percentage of total county population	Expected cases by population
1 = White	51	570
2 = Hispanic	23	257
3 = African American	4	45
4 = Asian, Pacific Islander	21	235
5 = Native American	1.0	10
	Total = 100%	Total = 1117

In order to run the chi-square goodness of fit test, open the file named: assign 6 prob 2 data.sav

· Under View > Value labels you can toggle between the variable category label (White, Hispanic, African American, Asian Pacific Islander, Native American) or the dummy codes (numeric representation) for the category label (1 = White, 2 = Hispanic, 3 = African American, 4 = Asian Pacific Islander, 5 = Native American). For this test, we want to compares the observed (actual) AIDS cases to the expected cases (frequencies, based on county population).

· Go to Analyze > Nonparametric tests > Chi square

· Move the AIDS variable to the “Test variable list” box

· Using the “Expected cases by population” numbers that correspond to each ethnic group in the table above, under “Expected values” select, “Values” then add the 5 population percentages that correspond with the frequency in the sample, using “Add” for each (570 > Add, 257 > Add, 45 > Add, 235 > Add, 10 > Add)

· Select “Descriptive” > Continue under “Options”

· Click “ok”

You will use the output for Questions 1-5:

Determine whether the make-up of AIDS cases follows the ethnicity of the general population of Neptune County. State the following:

1. Null Hypothesis

2. Decision

3. Reason for the Decision (paste the output that includes the statistical significance into Word)

4. Does it appear that the pattern of AIDS cases in Neptune County corresponds to the distribution of ethnic groups in this county? Why or why not?

5. You are asked to report your findings along with recommendations for prioritizing interventions by ethnic group to the County Health Commission. Write a one paragraph handout summarizing the findings and your recommendations. Also include the results, in APA style.

Assignment 6: Evaluation Form

Characteristics Assessed	Excellent	Adequate	Insufficient
Part 1.	Chi-Square Test of Association	5	4	0-3
Part 2.	Chi-Square Goodness of Fit Test	10	8-9	0-7
Total Points Earned: ____ / 15 Points Possible