RED YELLOW PINK BLUE BROWN GREEN BLACK PURPLE
RED YELLOW PINK BLUE BROWN GREEN BLACK PURPLE WHITE ORANGE GOLD BLACK YELLOW PURPLE PINK RED BLACK BLUE
SPAIN PORTUGAL ITALY DENMARK SWEDEN FRANCE ENGLAND NETHERLANDS GERMANY AMERICA MEXICO GREECE JAPAN NORWAY SCOTLAND WALES BELGIUM FRANCE SPAIN
Independent and Dependent variables • What is the IV for this experiment? • What is the DV for this experiment? • Exercise on page 12 -13.
Controlling Variables • Extraneous and Confounding Variables • If the extraneous Vs are not controlled or can’t be controlled then they may affect the DV. • If this happens then these variables are described as confounding variables. Confounding variables make results less RELIABLE.
Extraneous Variables • Excess noise/distraction – can be planned for. • Intelligence of participants in each group – can be controlled by putting people of equal IQ into each group. • Any others? E. g practice, fatigue, colour-blindness !! • By controlling these, we can assume that if the test times are lower for those in the ‘names of colours’ condition that this is the cause of a delay in completing the task.
Ways of controlling confounding and extraneous variables • Counterbalancing = balancing out or swapping the order that P’s do the conditions in • This prevents the order/practice/fatigue effect and helps to reduce demand characteristics • How was this done in our experiment?
Ways of controlling confounding and extraneous variables • Standardisation = keeping all aspects of the experiment the same for all P’s • Randomisation = mixing up the material presented to P’s so that it is in a random order • It is also advisable to randomly allocate P’s to conditions to prevent ‘bias’ i. e. making it equally likely that a P could appear in either condition (chance) • Relate these to our experiment!
More variable EXAMPLES • PARTICIPANT VARIABLES: an unrepresentative sample, the practice/order effect/intelligence etc. • SITUATIONAL VARIABLES: where the situation is not held constant and may adversely effect one group • RESEARCHER BIAS: the treatment of P’s by the researcher may not be consistent across groups
Demand Characteristics and Investigator Effects • • • • INVESTIGATOR BIAS Subjectivity Expectations Status Non-verbal cues PARTICIPANT BIAS 4 types of participant: faithful/cooperative/negativistic/evaluatively apprehensive Expectations Demand characteristics Hawthorn effect WAYS OF REDUCING BIAS Standardisation: instructions and procedure Single blind method Double blind method • Complete page 6 and 7
Plenary • • • Can you define …. . Independent variable Dependent variable Null Hypothesis One tailed hypothesis Two-tailed hypothesis Extraneous variable Confounding variable What other variables are there?
Welcome to AS Psychology • • • Mrs Rust Ashford Blog stcmpsy 13. wordpress. com textbooks Objectives Get to know each other Think about how psychologists find out what they know!
RED YELLOW PINK BLUE BROWN GREEN BLACK PURPLE WHITE ORANGE GOLD BLACK YELLOW PURPLE PINK RED BLACK BLUE
SPAIN PORTUGAL ITALY DENMARK SWEDEN FRANCE ENGLAND NETHERLANDS GERMANY AMERICA MEXICO GREECE JAPAN NORWAY SCOTLAND WALES BELGIUM FRANCE SPAIN
Independent and Dependent variables • What is the IV for this experiment? • What is the DV for this experiment? • Complete Exercise on page 12 -13
Controlling Variables • Extraneous and Confounding Variables • If the extraneous Vs are not controlled or can’t be controlled then they may affect the DV. • If this happens then these variables are described as confounding variables. Confounding variables make results less RELIABLE.
Extraneous Variables • Excess noise/distraction – can be planned for. • Intelligence of participants in each group – can be controlled by putting people of equal IQ into each group. • Any others? E. g practice, fatigue, colour-blindness !! • By controlling these, we can assume that if the test times are lower for those in the ‘names of colours’ condition that this is the cause of a delay in completing the task.
Ways of controlling confounding and extraneous variables • Counterbalancing = balancing out or swapping the order that P’s do the conditions in • This prevents the order/practice/fatigue effect and helps to reduce demand characteristics • How was this done in our experiment?
Ways of controlling confounding and extraneous variables • Standardisation = keeping all aspects of the experiment the same for all P’s • Randomisation = mixing up the material presented to P’s so that it is in a random order • It is also advisable to randomly allocate P’s to conditions to prevent ‘bias’ i. e. making it equally likely that a P could appear in either condition (chance) • Relate these to our experiment!
More variable EXAMPLES • PARTICIPANT VARIABLES: an unrepresentative sample, the practice/order effect/intelligence etc. • SITUATIONAL VARIABLES: where the situation is not held constant and may adversely effect one group • RESEARCHER BIAS: the treatment of P’s by the researcher may not be consistent across groups
Demand Characteristics and Investigator Effects • • • • INVESTIGATOR BIAS Subjectivity Expectations Status Non-verbal cues PARTICIPANT BIAS 4 types of participant: faithful/cooperative/negativistic/evaluatively apprehensive Expectations Demand characteristics Hawthorn effect WAYS OF REDUCING BIAS Standardisation: instructions and procedure Single blind method Double blind method • Complete page 6 and 7
Plenary • • • Can you define …. . Independent variable Dependent variable Null Hypothesis One tailed hypothesis Two-tailed hypothesis Extraneous variable Confounding variable What other variables are there?
OBSERVATION • Used as a more valid measure of human behaviour and experience • They are more ethical (providing there is informed consent, sometimes they might be unethical!) • Used when an experiment is not viable • There is no direct manipulation of the IV
Observational exercise • Work with a partner and take it in turns to observe each other. One of you will be Person A and the other will be Person B. • Person A should have a difficult task to do (e. g. answering a set of questions on something we have studied in Psychology) • Person B should have a boring task to do (e. g. copying from a book) • Each person should spend 5 minutes on their task, while the other person observes them, noting down any aspect of their partner’s behaviour
Observational Research Types: Natural – controlled (lab) Participant – non participant Covert – overt Ways of recording observations Time sampling- recording al aspects of behaviour during a short time • Event sampling – recording the no of times an event occurs e. g smiling. • • •
Reliability and Validity of Observations • Reliability • The issue is whether two observers would come up with the same observations. If they do then you have inter-observer reliability. To deal with this Observers are trained to use a coding system so that their observations are consistent. • Validity • Observations are watching people in a natural setting to gain high ecological validity, however they may lack generalisability, also if the coding system is flawed or if the observer is biased, then this may affect internal validity. To deal with this observations should take place in several settings with different observers.
– What data you want to gather? – Where you want to carry out your observation? – Who do you want to observe? – What sampling method are you going to use? – How are you going to record the data? – Who is going to record the data? – How long are you going to observe for? – How many times are you going to observe each group?
– What data you want to gather? – Where you want to carry out your observation? – Who do you want to observe? – What sampling method are you going to use? – How are you going to record the data? – Who is going to record the data? – How long are you going to observe for? – How many times are you going to observe each group? • • Frequency / nominal / quantitative In their playground at school. Boys and girls – at least 20 of each Volunteer and opportunity – the local schools that agree to take part. With a clipboard for all playtimes in a week at three different school. Note down all behaviours i witness and then put them into categories afterwards! me! 10 play sessions of 15 mins
Peer Assessment • Is their study a naturalistic observation or a laboratory observation? How do you know? • Describe one way in which the reliability of their observation of the play of boys’ and girls’ groups could have been improved. • Explain how any two factors might have affected the validity of their study. • Identify any ethical issues raised by their study. • Identify and explain how these ethical issues could be dealt with.
Measuring Reliability �Match the method of estimating reliability to the description Test-Retest reliability Split Half Reliability Inter-Rater reliability If the measure depends upon interpretation of behaviour, we can compare the results from two or more raters. Splitting a test into two halves, and comparing the scores in both halves The measure is administered to the same group of people twice If the results in the two halves are similar, we can assume the test is reliable If the results on the two tests are similar, we can assume the test is reliable If there is high agreement between the raters, the measure is reliable
Types of Validity • Internal validity – What happens inside the study, extraneous variables controlled? • External Validity – How our results can be generalised beyond the study – ecological validity, population validity/sampling • Validity of psychological measures – How well our methods of measurement actually measure what we intend
Validity of psychological measures • Content validity – Does the method used actually seem to measure what you intended? – Get an independent expert to check • Concurrent validity – How well does the measure agree with existing measures? – Check against an existing measure/test • Construct validity – Is the method actually measuring all parts of what we are aiming to test? – Check that test is appropriate to construct e. g are you asking the right questions to test IQ?
Reliability �When assessing the reliability of a study, we generally need to ask two questions 1. Can the study be replicated? 2. If so, will the results be consistent? � High vs low reliability
Measuring Reliability �Match the method of estimating reliability to the description (pg 163) Test-Retest reliability Split Half Reliability Inter-Rater reliability If the measure depends upon interpretation of behaviour, we can compare the results from two or more raters. Splitting a test into two halves, and comparing the scores in both halves The measure is administered to the same group of people twice If the results in the two halves are similar, we can assume the test is reliable If the results on the two tests are similar, we can assume the test is reliable If there is high agreement between the raters, the measure is reliable
Exam style questions – answer on separate piece of paper. 15 minutes. • A researcher is going to a primary school playground to observe how aggression differs between boys and girls. • (a) Outline one advantage and one disadvantage of using a natural setting observation in this research. [3] • • (b) Identify one issue of reliability in this research and describe how you could ensure reliability. [3] • • (c) Identify one issue of validity in this research and describe how you could ensure validity. [3] • P. S In the exam there will be 6 questions like this !
Quick Test • Give two examples of situation variables that might affect validity • Give two examples of participant variables • Give one issue which will affect the internal validity of a study • Give one issue which will affect the reliability of a study.
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