• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11

The aim of this investigation was to look at the reliability and validity of Hans Eysenck's EPI Test. The EPI questionnaire comprises of items of a 'yes/no' variety.

Extracts from this document...

Introduction

Abstract

The aim of this investigation was to look at the reliability and validity of Hans Eysenck’s EPI Test. The EPI questionnaire comprises of items of a ‘yes/no’ variety. They are essentially intended as research tools (as opposed to diagnostic tools for use in clinical settings) and, as such, ‘they are regarded as acceptable, reliable and valid’ (Kline 1981, Shackleton and Fletcher, 1984).The Alternative Hypothesis was that there would be a positive correlation between the E and N scores for forms A and B of the EPI. The Null Hypothesis was that there would not be a positive correlation between the scores for forms A and B, and any such found relationship would be down to chance factors operating.

The correlation study was carried out because we were looking for a relationship between the E scores and the N scores for forms A and B of Hans Eysenck’s EPI Test. The independent variable and dependent variable were not operationalised in this case because an experimental method was not being used and this investigation used test re-test reliability. A repeated measure design was used because it was quick, economical and cancelled out individual differences. Eighteen naïve psychology students, male and female were used for this investigation.  An opportunitive sample was used because it was quick, easy and could be carried out in a classroom.

The results, taken from the Raw Score Data table and scatter graph showed evidence of a positive correlation. However, to accept that this result was significant, we subjected the data to further statistical analysis.

...read more.

Middle

-1.5

2.5

6

16

17

11

9.5

16.5

2

4

7

23

23

18

17

23

1

1

8

5

6

1

1

5.5

0

0

9

12

13

7

4

12.5

3

9

10

10

19

4

12

14.5

-8

64

11

22

20

17

13.5

21

3.5

12.25

12

19

17

14

9.5

18

3.5

12.25

13

14

18

9

11

16

-2

4

14

11

14

5.5

5.5

12.5

0

0

15

13

15

8

7

14

1

1

16

15

16

10

8

15.5

2

4

17

20

21

15

16

20.5

-1

1

18

21

21

16

16

21

0

0

Σ d ² = 126

rs =      1-    6Σ d ²

                      n(n² - 1)

         =      1-     6 x 126      

                          18 (18² - 1)

         =      1-     6 x 126

                          18 (324 -1)

         =      1-     6 x 126

                         18 x 323

         =       1-     756

                          5814

         =       1-    0.130031

         = 0.869969

The Spearman’s coefficient of rank correlation for the relationship between the ‘E’ scores of form A and B is 0.87 (2dp). This is a strong positive correlation.  

image01.png

A result table illustrating the outcome of Eysenck’s personality inventory, illustrating the ‘E’ scores for form A and B.

...read more.

Conclusion

Limitations of design

The main limitations of the method in this investigation are that a correlation study establishes a relationship, but not a cause and effect relationship. The only way to be certain about this result would have been to devise an experiment to test the reliability of the EPI. However, the investigators failed to achieve this at the design stage.

Design Problems

The design used was a repeated measure and problems with this could include order effects such as learning, fatigue or boredom and subjects given the same test may do better due to practice. Also demand characteristics may become a problem; as the subject completes both conditions of the research, they may guess the aim of the investigation and act differently.

Conclusion

It has already been stated that this investigation was a one tailed test, with the number of people being eighteen. The calculated value for the ‘E’ score was 0.87. In order to be significant it had to exceed the critical table value, and in this case it did, at 0.01 level. Therefore we accepted the Alternative Hypothesis that there would be a positive correlation between the ‘E’ scores for forms A and B, and we rejected the Null .

We also used this comparison for the ‘N’ score. With the number of people being eighteen. The calculated value for the ‘N’ score was 0.90. In order to be significant it had to exceed the critical table value, and in this case it did, at 0.01 level. Therefore we accepted the Alternative Hypothesis that there would be a positive correlation between the ‘N’ scores for forms A and B, and we rejected the Null .

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Probability & Statistics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Probability & Statistics essays

  1. The mathematical genii apply their Statistical Wizardry to Basketball

    Lee, having a lower expected mean value than Dom, is shown to be the better free-thrower as he takes an average of approximately three shots to score, unlike four shown in Dom's case. The total number of shots can be a very rough indicator of who seems to be the better free thrower.

  2. Original Writing: Dramatic Monologue - Monologue of a Disturbed Personality

    I told him about my family and he has about his. He is here again changing my bandages. "Lizzie...have you been following my instructions because I fear something is happening.

  1. Investigating the Relationship Between the Amount of Money a Football Club Receives and its ...

    24 27 1 10 12 11 33 47 11841 �2,060,000 -25 1 Crewe Alex 18 46 7 6 10 27 35 5 6 12 27 43 48 10046 �2,082,000 -24 1 Crystal Palace 14 46 11 10 2 43 26 3 6 14 15 45 58 26400 �2,000,000 -13 1

  2. Design an investigation to see if there is a significant relationship between the number ...

    Also count the number of bladders, recording the information in a results table as shown. 7. Using a tape measure to measure, repeat steps 3-6 every 2 metres along the belt transect (100m rope), so that in total you've placed 50 quadrats over the 100m transect.

  1. I am going to design and then carry out an experiment to test people's ...

    This is hard to control so unfortunately this may affect my results However, it was noticed that some people did not catch the ruler at all, completely missing it. It was decided that if this happened, a reading of 30 would be taken as the recorded time.

  2. "The lengths of lines are easier to guess than angles. Also, that year 11's ...

    11 line estimates were more spread out than the year 9 line estimates. These tables are made for use in with the scatter graphs. They show Spearman's Coefficient of Rank. This is basically to find the correlation of the data.

  1. Forensic Examination of Drugs by Thin Layer Chromatography.

    In the forensic lab further examination of the samples would be carried out to determine the composition of the questioned powders, remember the TLC is only a screening test & would usually be carried out after a presumptive test has been used.

  2. Statistics - My aim is to investigate whether it is possible to gain information ...

    representative, I used the RAND function in Microsoft Excel to get the random page number, line number and word number. Method For this investigation, I am finding out whether it possible to gain information about authorship of a text. I will be using and adult text and a child text.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work