LaboratoryAssignment

Crosstabs and Chi-Square

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****ASSIGNMENT 1: CHI SQUARE QUESTIONS ****

Experiment

Some researchers have suggested that there are two main types of personality: Type A and Type B. Individuals with Type A personality

are characterized as being conscientious and competitive. They strongly desire success and typically present with higher levels of

stress. Conversely, individuals with Type B personality are typically less stressed and tend to be more laconic, relaxed and less

concerned with competition.

Due to the higher levels of stress experienced by those with Type A personality, health insurance risk evaluators are interested in

knowing whether individuals with Type A personality are at greater risk of having a heart attack.

You are hired as a researcher to investigate this research question. You take a random sample of 40 individuals aged between 40 and

60years and assess their personality to determine whether they possess a Type A or Type B personality. You then ask them whether they

have experienced a heart attack before (yes/no). You then run a Chi-Square test of independence to determine whether there is a

relationship between Personality Type (A or B) and Heart Attack incidence(Yes or No) and obtain the following data:

_____________________________________________________________

Personality Type * Heart Attack Incidence Crosstabulation

Heart Attack Incidence Total

Yes No

Personality Type Type A Personality Count 15 7 22

Expected Count 9.9 12.1 22.0

Type B Personality Count 3 15 18

Expected Count 8.1 9.9 18.0

Total Count 18 22 40

Expected Count 18.0 22.0 40.0

Chi-Square Tests

Value df Asymp. Sig. (2-sided)

Pearson Chi-Square 10.615a 1 .001

Likelihood Ratio 11.309 1 .001

Linear-by-Linear Association 10.350 1 .001

N of Valid Cases 40

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Questions

1. Under what experimental conditions would it be appropriate to run a chi-square test of independence?

/2 Marks

2. Complete the following chi-square table. Insert both the observed and expected frequencies(expected frequencies should appear

in parentheses).

Heart Attack No Heart Attack

Type A

______________

( ______________ )

______________

( ______________ )

Type B

______________

( ______________ )

______________

( ______________ )

/1 mark

.5 mark correctly entering observed values

.5 mark correctly entering expected values

3. Is personality type associated with heart attack incidence? If so, describe the relationship? Use appropriate statistics to

support your answer.

/ 2 marks

1 mark for correct answer

1 mark for correctly describing the relationship between the variables

4. With help from your text book and the previous example, report the results of the analysis in APA format including all relevant

information

/ 5 marks

TOTAL: /10 Marks

Research Methods in Psychology A (HPS201/HPS771)

LaboratoryAssignment

Assignment 2: Comparing Means and t-tests

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Experiment

Some researchers have proposed that children from rural regions of Victoria develop better motor skills than those from Metropolitan

Victoria. As a Developmental Psychologist, you conduct an experiment to test this theory. You take a sample of 60 17 year-olds who grew

up and continue to live in ‘rural’ Victoria, and another 60 17-year olds who grew-up and continue to live in ‘metropolitan’ Victoria.

You then assess each participant’s motor ability using a standardized test of motor skill [M=100, SD=15)].

You run an independent samples t-test to determine whether the mean motor ability of ‘rural’ children is different from the mean motor

ability of ‘metropolitan’ children. Based-on previous research, you would predict that the ‘rural’ group would have better motor skills

than the ‘metropolitan’ group. You obtain the following data:

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The first two questions do not require you to use the above SPSS output.

1. Under what experimental conditions would it be appropriate to conduct a single-sampled t-test and in such a scenario, why would

a researcher adopt a single-sampled t-test rather than a z-test?

/ 2 Marks

1 Mark for each correct answer

2. A researcher wishes to determine whether the mean depression rating of a group of elderly men changes after they have undergone

a mental health workshop. Each participant completes the Beck Depression Inventory (scores range from 0 to 63) before and after the

workshop. What kind of t-test should the researcher use to compare the mean depression rating of participants before and after the

workshop? Given that there are 3 types of t–test, what makes the other two types of t-test inappropriate for this scenario?

/ 2 Mark

1 Mark for each correct answer

The remaining questions relate to the above SPSSoutput.

3. Has the assumption of homogeneity of variance been met or violated? Use statistical information to support your answer.

/1 marks

.5 mark for correct answer

.5 mark for correct use of statistics

4. Based on a visual inspection of the statistics in the‘group statistics’ box in the SPSS output (i.e. not the independent

samples t-test), do you anticipate that there will be a significant difference between the mean motor abilities of the ‘rural’ and

‘metropolitan’ groups? Justify your answer.

/ 2 mark

5. How would you interpret the results of this analysis? Write a short summary paragraph in APA format describing this analysis

including all relevant information.

/ 3 marks

/10 Marks

Research Methods in Psychology A (HPS201/HPS771)

LaboratoryAssignment

Assignment 3: Correlation

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Experiment

You are hired as an Industrial Psychologist by a local Coffee shop to investigate the factors that influence how much coffee is being

sold during a day. You believe that the daily temperature may be associated with coffee sales. Accordingly, you visit the coffee store

on 70 occasions throughout the year. Each time you record the number of coffees that were sold during that day, as well as the daily

temperature high.

You run a Pearson’s correlational analysis on the data to investigate the relationship between daily coffee sales and daily temperature

high. The data are as follows:

Descriptive Statistics

N Minimum Maximum Mean Std. Deviation

Daily Temperature High (degrees Celsius) 70 7.00 38.00 20.9429 7.88851

No. coffees sold 70 12.00 82.00 38.1286 18.38235

Valid N (listwise) 70

Correlations

Daily Temperature High (degrees Celsius) No. coffees sold

Daily Temperature High (degrees Celsius) Pearson Correlation 1 -.759**

Sig. (2-tailed) .000

N 70 70

No. coffees sold Pearson Correlation -.759** 1

Sig. (2-tailed) .000

N 70 70

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The first two questions do not require you to use the above SPSS output.

1. Describe the type of research question where either a Pearson correlational analysis or a Chi-square test of independence could

be used to answer it.

/1 mark

2. Based on the type of research question you described above in ‘question 1’, explain when a Pearson correlational analysis would

be used rather than a Chi-square test of independenceand vice versa.

/ 2 marks

The remaining questions relate to the above SPSSoutput.

3. What type and strength of relationship was found between daily coffee sales and daily temperature high? Use statistical

informationto support your answer.

/2 mark

1 Correct type and strength

1 Correct use of statistical information

4. Using an appropriate statistical measure, write a short statement explaining what percentage ofvariability in daily coffee sales can

be attributed to the daily temperature high?

/2 Marks

1 Correct answer

1Use of correct statistical measure

5. How would you interpret the results of this analysis? Write a short paragraph in APA format describing this analysis including all

relevant information.

/3 Marks

/10 Marks