4.2.3.1 HYPOTHESES

Question 1

what is a hypothesis?

Answer 1

• a precise and testable statement of prediction about the outcome of an experiment

Question 2

what does a hypothesis involve and require?

Answer 2

1) usually involves proposing a possible relationship between two variables:
- the independent variable and the dependent variable

2) a requirement of a hypothesis is that it can be tested against reality
- can be supported or rejected

Question 3

what is a null hypothesis?

Answer 3

• has to be written as well as the experimental hypothesis
• the experimenter states there’s no relationship between the IV and the DV
  -> if there’s a relationship, it’s merely due to statistical chance
• one variable doesn’t affect the other
• will be no change / difference between variables
• states results aren’t significant in terms of supporting the idea being investigated

Question 4

what’s an alternative hypothesis / experimental hypothesis?

Answer 4

alternative hypothesis is called the experimental hypothesis when the method of investigation is an experiment

• states that there’s a relationship between the two variables being studied
• one has an effect on the other
• predicts what change(s) will take place in the DV when the IV is manipulated
• states the results aren’t due to chance
  that they’re significant in the terms of supporting the theory being investigated

Question 5

there’s two types of experimental hypothesis.
what are they?

Answer 5

1) directional

2) non directional

Question 6

what should a good hypothesis include?

Answer 6

1) all conditions / groups
- eg) what will happen in one group and the control group

2) prediction
- (will be)
- future tense not past

3) check if it should be directional or non-directional

4) operationalise
- DV should be measurable

4) should be short / concise and comprises clear and simple language

5) identify the key variables in the study

Question 7

what does a hypothesis need to contain?

Answer 7

• the independent variable
• the dependent variable
• both IV and DV need to be operationalised (need to have a way of testing them)

ie) you would need to measure aggression by looking at how many times a person swore, shouted, hit something
rather than just, i’m going to measure aggression

Question 8

what’s a directional hypothesis?

Answer 8

• states what the experimenter thinks will happen in their study
• tend to be used when you know, from previous research, what will happen in your study
• one tailed
• suggests direction of results

eg) in a test of completing a word search, ppts will find more words when they’re eating chocolate than when they’ve not eaten chocolate

Question 9

what’s a non-directional hypothesis?

Answer 9

• used when the experimenter isn’t sure what’ll happen and there’s no previous research to suggest what the result might be
  -> or there’s a conflicting body of research
• doesn’t suggest a direction (experimenter is sitting on the fence)
  -> only a difference
• two tailed
• IV will have an effect on the DV

eg) in a test of recall, there will be a difference between the number of words correctly recalled by ppts when they’ve been listening to heavy metal as compared to recall when they’ve been listening to pop