Personal Investigation - The Effetcs Of Context On Perception

Question 1

What is the Hypothesis for this Experiment?

Answer 1

Participants who are given visual stimuli which are set in different contexts are more likely to perceive the objects incorrectly (i.e. State the wrong length/size) than participants who are given the same visual stimuli but in the same contexts

Question 2

Why was a Directional Hypothesis Used?

Answer 2

Previous research suggests this

Question 3

What is the Null Hypothesis for the Experiment?

Answer 3

There will be no difference in answers between participants who are given visual stimuli in the same context and those given visual stimuli in different contexts

Question 4

What is the Independent Variable?

Answer 4

Visual stimuli in same contexts/visual stimuli in different contexts

Question 5

What was the Dependent Variable?

Answer 5

The score achieved (number of correct answers)

Question 6

How were the Other Variables Controlled?

Answer 6

• The same visual stimuli was given to participants in the experimental group
• The same visual stimuli was given to the participants in the control group
• The time given to answer the questions was the same for participants
• The environment - same for both groups
• Where the participants sat during the test (they sat apart to ensure no cheating/copying)
• Same instructions were given to all the participants

Question 7

What were the Possible Confounding Variables?

Answer 7

• Some may have seen these visual stimuli previously and therefore knew the answers
• The mood participants were in. If they were in a negative mood, they might not have tried very hard to get the answers correct
• Demand Characteristics - even though a cover story was used, some may have guessed the true purpose + acted accordingly
• Intelligence Levels - might be that one group were more intelligent than the other

Question 8

What was the Experimental Design Used?

Answer 8

Independent group Design

Question 9

Describe the Participants Used in this Experiment

Answer 9

• 30 participants (15 in each condition)
• Equal number of boys and girls
• All 16 years of age (year 11)

Question 10

What was the Sampling Technique Used in this Experiment?

Answer 10

Opportunity sampling - Yr 11 pupils who were willing to take part in the investigation

Question 11

What are the Advantages of Using Opportunity Sampling?

Answer 11

• Because you use the first suitable participants you can find it means it takes less time to locate
• Easy to get hold of participants as you use the most willing people so it is quick to gain a sample

Question 12

What are the Disadvantages of Using Opportunity Sampling?

Answer 12

• Biased sample because the sample is drawn from a small part of the target population
• Selection bias as the researcher is likely to pick those for example who make eye contact

Question 13

Describe the Descriptive Statistics for the Experiment

Answer 13

• Total + mean were recorded for both conditions
• Mean is the most sensitive + makes use of all data
• Total for same context = 85
• Total for different context = 41
• Mean for same context = 5.67
• Mean for different context = 2.73

Question 14

What was the Procedure for this Study?

Answer 14

1. Before the investigation a pilot study was conducted - consisted of 12 psychology students - done to ensure that the visual stimuli that were going to be used were appropriate + that the length of time given to judge the stimuli was appropriate
2. 2 psychology students went into a year 11 class + asked if they were willing to take part in an investigation. They were told the investigation was on gender + vision (cover story used to avoid demand characteristics)
3. They were then split into two groups of 15 and placed in two different classrooms but they were very similar classrooms but they were very similar type classrooms
4. Participants sit at different desks to prevent cheating
5. Sheets of paper were handed out to group 1. This had 10 questions on it relating to visual stimuli. For example, they had to state whether the lines/circles were the same/different length/size etc. Out of 10 visual stimuli and questions, only 6 were relevant to the investigation (critical visual stimuli). These were visual stimuli were set in different contexts
6. When participants were all ready to begin the task, they turned the sheet of paper over and began to answer the questions on the sheet
7. At the same time but in the other classroom, sheets of paper were handed out face down, to group 2. With this group, there were also 10 visual stimuli + questions but the 6 critical visual stimuli were set in the same context. Again, they had to state whether the lines/circles were the same/different
8. Two and a half minutes were given to both groups to answer the questions. A stopwatch was used to tie this
9. The sheet of paper were the taken in and marked out of six for each groups. The two groups’ scores were compared

Question 15

What Graphical Representation was Used For This Investigation?

Answer 15

• A bar chart can be used to display the information because it can show categories easily
• It’s easy to construct and understand

Question 16

Describe the Inferential Statistics for the Experiment

Answer 16

Mann Whitney used because:

• the data is at least the ordinal level
• an independent design was used
• the investigation was looking at a difference between scores of a group given visual stimuli in the same context and a group given the same visual stimuli but in different contexts

Question 17

What were the Findings of the Investigation?

Answer 17

The findings showed that there was a significant difference between the group who viewed the visual stimuli in different context and the context and the group that visual stimuli in same contexts

• Since the observed value (U=0) is lower than the critical value of 72 at 0.05 level of significance for a one tailed test, we can say there is a significant difference between the different context group and the same context group.
• We can therefore accept the experimental hypothesis and reject the null hypothesis.
• The chances that the null hypothesis is correct is less than 5%
• the findings showed that the participants given the visual stimuli is different contexts perceived them incorrectly in terms of their size/length

Question 18

What is the Conclusion of this Investigation?

Answer 18

• There was a significant result between the visual stimuli in the same context and the visual stimuli in the different context.
• This suggests the the context of visual images affects perception

Question 19

What Were the Possible Issues with Reliability?

Answer 19

Internal Reliability
We established this by doing the split half method. This is where we took the first 3 critical questions of the test and compared them with the second 3 critical questions of the test. We found there was a high degree god similarity between the two sets of scores (a reason why the internal reliability was high because a pilot study was conducted beforehand)

Observer Reliability
To establish this, two observers marked tests. Their scores were then compared. It was found that their scores were consistent/the same so observer reliability was high

External Reliability
The extent to which something is consistent overtime
- we could have done the Test-Retest Method - after testing initially we could have done the test again with stimuli at the same level of difficulty- similar results would have meant high external reliability

Question 20

What were the Potential Issues with Validity?

Answer 20

INTERNAL VALIDITY

• Extent to which the researcher measures what thy intended to measure
• We had to make sure that we were measuring the effects of context on perception of visual stimuli
• This was achieved through controlling all possible confounding variables

Population Validity

• This study was low in population validity as only year 11 pupils from our school were used
• It would would’ve been better if we used students of different ages/schools

Ecological Validity

• The setup of the experiment was also quite controlled + artificial therefore quite low in ecological validity
• A field experiment would have improved ecological validity

To assess validity, we used content validity used content validity where our psychology teacher looked very carefully at our procedure

Question 21

What were the Possible Confounding Variables that were Controlled?

Answer 21

• Ensured the environment was the same for both groups
• They sat separately so copying/cheating was not an issue
• The question paper were turned upside down so they all had the same length of time to look at stimuli
• A stop watch was used to ensure the correct time was given to each participant
• A cover story was used to reduce demand characteristics
• Instructions were written down to ensure everybody had the same information
• Researcher bias - researcher may influence the groups by the way in which they communicate with the participants. This was reduced by having the 2 groups together + instructions were read out to both at the same time.
• Only 6 questions were relevant to the investigation, another 4 visual stimuli and questions were added so that participants did not guess the purpose of the investigation

Question 22

What were the Potential Ethical Issues with this Investigation?

Answer 22

• Deception
• Confidentiality
• Informed consent
• Psychological harm

Question 23

What was the Issue of Deception?

How was it Dealt With?

Answer 23

• We told the participants that the investigation was on the effect of gender on vision
• This wasn’t true but was necessary to reduce demand characteristics + it also wasn’t a high level of deception
• Dealt with afterwards by debriefing them + informing them of their right to withdraw their data if they wished (retrospective informed consent)

Question 24

What was the Issue of Confidentiality?

How was it Dealt With?

Answer 24

• This could have been an issue in their personal details had been shared with others
• Dealt with by keeping their personal confidential.
• No names were recorded when data was collected

Question 25

What was the Issue of Informed Consent?

How was it Dealt With?

Answer 25

• The headmaster gave permission for the investigation to be carried out and also they were 16 years of age
• Participants were not doing anything different to what they would have been doing in lessons
• Dealt with by debriefing the participants afterwards + giving them the right to withdraw their data if they wished

Question 26

What was the Issue of Psychological Harm?

How was it Dealt With?

Answer 26

• Students could have felt embarrassed/stupid if they didn’t understand the questions/know the answers
• Dealt with by informing them at the start + throughout the experiment that they could withdraw at anytime + their data would be destroyed

Question 27

How would You Improve the Investigation?

Answer 27

• We could have used more critical questions rather than just 6 in each condition so that we had more data to support the experimental hypothesis
• More participants + from other schools should have been used to improve population validity, making the results more generalize to the population
• A field experiment could have been used to improve the ecological validity. This experiment was quite artificial as people are rarely asked to decide whether visual images are the same/different therefore a field experiment of some sort would increase the ecological validity
• Could have matched participants on intelligence to ensure two equal groups f participants in the same/different context groups which would improve the validity