Reliability and Validity.

Question 1

In order for an experiment to be reliable we tend not to trust one single _______. What do we do?

Answer 1

Measure.

We tend to repeat the experiment several times then take an average.

Question 2

If the experiment only has 2 trials, what can we say about the reliability?

Answer 2

That the reliability is low.

Question 3

How would we increase/improve the reliability?

Answer 3

Take a series of trials.

Do 20 trials instead of 2.

Question 4

Name this:

• How dependable is your measure?
• Is it consistent over time?
• Would you get the same measure if you do it again?

Answer 4

The reliability of our measurement.

Question 5

Apart from increasing the number of trials, how else can we improve reliability?

Answer 5

By controlling extraneous variables.

Question 6

If we don’t control extraneous variables, it becomes ____________.

Answer 6

Confounding.

Question 7

So name the 2 main ways to Improve Reliability.

Answer 7

1. Increase the numbers of trials (and find the average).

2. Control Extraneous Variables.

Question 8

To ensure the measure of something is reliable, take several ______ of the measure for each person, under ________ conditions and then find the _______ measure.

Answer 8

Readings. Controlled, Average.

Question 9

More trials = _______ reliability.

Answer 9

Greater.

Question 10

How do we ensure the reliability of measurements is high?

Answer 10

• Take repeated readings of variable and use average value

- Control Extraneous Variables.

Question 11

What is meant by Validity?

Answer 11

To what extent is your measure and appropriate measure of what you are trying to measure?

Question 12

Today, ______ is still an area of considerable debate.

Answer 12

Validity.

Question 13

Validity is about how ______ your measure is.

Answer 13

Appropriate.

Question 14

Name this.

• Are the measures appropriate?
• Are they measuring what they think they are measuring?

Answer 14

Validity.

Question 15

Validity has 2 main distinctions. Name these.

Answer 15

• Internal Validity

- External Validity

Question 16

What is validity very relevant to?

Answer 16

Design considerations of an experiment.

Question 17

Why is validity important?

Answer 17

The experiment needs to be a proper, fair test that is representative of real life.

Question 18

The experiment must be _____ for the data to be useful.

Answer 18

Valid.

Question 19

What does Internal Validity refer to?

Answer 19

• Was there a real effect? (eg. not fluke, no mistakes, right test used etc.)
• Were the changes seen in the DV solely due to manipulation of the IV? (were all extraneous variables controlled etc.)

Question 20

Internal Validity measures if there was any ____ to ________.

Answer 20

Threats, Validity.

Question 21

What does External Validity mean?

Answer 21

How generalizable are the results…

• To Different Populations
• To Different Locations
• To Different Times
• To Different Measurements?

Question 22

In order to have external validity for different populations, what must we have?

Answer 22

A varied sample. (different ages, genders etc.)

Question 23

Explain what is meant by Ecological Validity?

Answer 23

Are our results valid in different locations eg. do the same study in 2 different places.

Question 24

If you have the same results/affect from your experiment in two different places, what can be said?

Answer 24

Your experiment has a high ecological validity.

Question 25

Explain what we mean in terms external validity, by the results being the same at different times?

Answer 25

This means- would the results from an experiment in the past (1970) still be relevant/valid today?

Question 26

_______ validity takes into account if we can use a different ________ and still get the same results.

Answer 26

External, Measurements.

Question 27

We can use different ______ to measure the same thing eg. aggression.

Answer 27

Techniques/Measurements