Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Validity! We need to 
find out if our 
research is sound. 
Do our tests 
measure what they 
claim to measure?
Are techniques used to collect data in tests, 
questionnaires, interviews and observations measuring 
what is claimed? For...
We need to be 
able to measure 
or observe 
something time 
after time and 
produce the 
same or similar 
results
I want to measure intelligence. If the same 
person sits the test on several occasions and 
the results change each time, ...
The test also arguably lacks validity because the 
scores are meaningless
If I test my participants again several months 
later and their scores remains consistent, I can 
say the test is reliable...
Is an A level in Psychology a valid and reliable 
assessment of your performance in Psychology.
This measures consistency from one occasion to another – 
the same result should be found on different days, in different ...
Participants take the same test on different occasions – a high correlation between 
test scores indicates the test has go...
This refers to the consistency of a researcher’s behaviour. 
A researcher should produce similar test results, or make sim...
In observational 
studies this is known 
as inter-observer 
reliability – observers 
have to agree on what 
they see and c...
1. Increase reliability by standardising instructions 
2. Carry out a pilot study to improve procedures and 
materials 
3....
This measures the extent to which a test or procedure is 
consistent within itself, i.e., questionnaire items or questions...
Odds/Evens Top/Bottom 
Compares a participant’s performance on two halves of a test or questionnaire – 
there should be a ...
Would you see this as bullying or 
horseplay in the playground? 
You would see 
this from your 
own subjective 
viewpoint ...
Measuring Reliability 
Match the method of estimating reliability 
to the description 
Test-Retest 
reliability 
If the m...
The tool is measuring what it is 
intending to measure 
= 
= 
The findings can be generalized 
beyond the context of the 
...
Does our 
measuring 
tool appear 
to be doing 
what it 
should? 
Face 
validity: 
One or more 
judges assess 
whether the ...
Does the content of a 
test cover everything in 
the area of interest? 
Content validity: 
More rigorous – 
experts in the...
Improving internal validity 
• Single blind procedure - reduces demand 
characteristics 
• Double blind procedure ….
Population Validity 
Can we generalise 
findings from our 
research participants 
to other population 
groups?
Can we apply our findings to 
other contexts and situations 
outside of the research setting? 
Ecological Validity
Improving external validity 
• Sample must be representative of target 
population and be unbiased….. 
• Research situatio...
Upcoming SlideShare
Loading in …5
×
Upcoming SlideShare
Presentation Validity & Reliability
Next
Download to read offline and view in fullscreen.

13

Share

Download to read offline

A" Research Methods Reliability and validity

Download to read offline

Research methods

Related Books

Free with a 30 day trial from Scribd

See all

A" Research Methods Reliability and validity

  1. 1. Validity! We need to find out if our research is sound. Do our tests measure what they claim to measure?
  2. 2. Are techniques used to collect data in tests, questionnaires, interviews and observations measuring what is claimed? For example was the Strange Situation really measuring attachment style?
  3. 3. We need to be able to measure or observe something time after time and produce the same or similar results
  4. 4. I want to measure intelligence. If the same person sits the test on several occasions and the results change each time, then that test lacks reliability
  5. 5. The test also arguably lacks validity because the scores are meaningless
  6. 6. If I test my participants again several months later and their scores remains consistent, I can say the test is reliable, but it might still lack validity.
  7. 7. Is an A level in Psychology a valid and reliable assessment of your performance in Psychology.
  8. 8. This measures consistency from one occasion to another – the same result should be found on different days, in different labs , observations or interviews, by different researchers I exposed these teenage brain cells to 1000 PowerPoint slides last Monday and they’re all dead I thought that was a fluke but they seem to be shrivelling after only five minutes!
  9. 9. Participants take the same test on different occasions – a high correlation between test scores indicates the test has good external reliability . Timing is crucial. Why? January June I hope that’s the right answer this time
  10. 10. This refers to the consistency of a researcher’s behaviour. A researcher should produce similar test results, or make similar observations or carry out interviews in the same way on more than one occasion. Thanks for taking part today. Any problems and I’ll be right over. Take your time. Right. Let’s get on. Fast as you can. How much longer before I can get in the pub and relax my facial muscles?
  11. 11. In observational studies this is known as inter-observer reliability – observers have to agree on what they see and carry out the same procedure Consistency between different researchers working on the some study is very important for reliability
  12. 12. 1. Increase reliability by standardising instructions 2. Carry out a pilot study to improve procedures and materials 3. You will be thoroughly trained in the use of materials and procedures prior to our study taking place
  13. 13. This measures the extent to which a test or procedure is consistent within itself, i.e., questionnaire items or questions in an interview should all be measuring the same thing Do you like to keep to deadlines? Do you get impatient driving? Do you like cheese? Do you like doing several tasks at once? Do you like chocolate? Do you get easily irritated? Are you competitive? This interviewer seems a little confused about Type A personality traits
  14. 14. Odds/Evens Top/Bottom Compares a participant’s performance on two halves of a test or questionnaire – there should be a close correlation between scores on both halves of the test. Questions in both halves should be of equal quality for good internal reliability.
  15. 15. Would you see this as bullying or horseplay in the playground? You would see this from your own subjective viewpoint – we’re biased by experience and expectation Observers must agree about what they are observing – they need to use standardised behavioural categories
  16. 16. Measuring Reliability Match the method of estimating reliability to the description Test-Retest reliability If the measure depends upon interpretation of behaviour, we can compare the results from two or more raters. If the results in the two halves are similar, we can assume the test is reliable Split Half Reliability Splitting a test into two halves, and comparing the scores in both halves If the results on the two tests are similar, we can assume the test is reliable Inter-Rater reliability The measure is administered to the same group of people twice If there is high agreement between the raters, the measure is reliable
  17. 17. The tool is measuring what it is intending to measure = = The findings can be generalized beyond the context of the research situation
  18. 18. Does our measuring tool appear to be doing what it should? Face validity: One or more judges assess whether the test seems appropriate and suggest changes if necessary
  19. 19. Does the content of a test cover everything in the area of interest? Content validity: More rigorous – experts in the field systematically examine the tool’s components and compare them with set standards They have to agree the content is appropriate
  20. 20. Improving internal validity • Single blind procedure - reduces demand characteristics • Double blind procedure ….
  21. 21. Population Validity Can we generalise findings from our research participants to other population groups?
  22. 22. Can we apply our findings to other contexts and situations outside of the research setting? Ecological Validity
  23. 23. Improving external validity • Sample must be representative of target population and be unbiased….. • Research situation must reflect real life situation e.g. debate over Milgram….Strange Situation
  • RamsheenaMariyam

    Oct. 31, 2019
  • Pallu03

    Apr. 23, 2019
  • MiaadAlzubaidy

    Dec. 17, 2018
  • ramki6

    Sep. 17, 2018
  • ELMEHDIELHAMYDY

    Nov. 26, 2017
  • AwotweEdmund

    Nov. 8, 2017
  • SadaketAli

    Sep. 19, 2017
  • SalihaMaryam

    May. 31, 2017
  • KomalBansal20

    May. 18, 2017
  • IlkerAdemoglu

    Apr. 17, 2017
  • fisehakebede

    Mar. 26, 2017
  • DrKwasiSampong

    Nov. 1, 2016
  • zainabamjad509

    May. 7, 2015

Research methods

Views

Total views

12,868

On Slideshare

0

From embeds

0

Number of embeds

448

Actions

Downloads

630

Shares

0

Comments

0

Likes

13

×