All homework assessments to go in your folder in order. With a homework cover sheet Chose a piece of homework to make improvements on. Use a different colour or clearly label it DIRT. Update the homework cover sheet,

Dedicated, Improvement & Refection Time (DIRT ) You do the work You get the Feedback You get time to respond to the feedback and make improvements. If it is not excellent it is not finished You move your work closer to excellence Respond to any questions Look up answers in the textbook Ask a friend or compare your work to theirs

I can Explain how to control extraneous variables Distinguish between directional & non directional hypotheses Construct operationalised hypotheses Name and evaluate different sampling methods. Name and evaluate three experimental designs Name and evaluate lab, field and Natural experiments Distinguish between Reliability & Validity

A03 - How Science Works Observe human behaviour Develop explanations (theory)/hypotheses Test hypotheses Collect results/data Draw conclusions Analyse data/graphs/inferential statistics

What is an experiment? A research method in which: There is an independent variable (IV) manipulated by the researcher. The effects of the IV on another variable are observed or measured. This variable is called the dependent variable (DV). The participants are allocated randomly to the conditions.

Experimental method PPs revise using concept maps Test of learning Score PPs revise using note-taking Test of learning Score IVDV Conditions

Methods Experimental Lab Field Natural Non Experimental Case study Correlation Observations Interview questionnaire

Extraneous Variables Explain how to control extraneous variables

Control of Extraneous variables Psychologists try to control extraneous variables so that they don’t become confounding variables. Extraneous variables can impact on the internal validity of a study. If they are not controlled they can confound the results because the change in the DV may be due to the extraneous variables rather than IV Explain how to control extraneous variables

Controls There are 3 types of variables to control. Participant variables Situational variables Experimenter variables Explain how to control extraneous variables

Refers to situation where participants form an interpretation of the experiment's purpose and unconsciously change their behaviour accordingly Explain how to control extraneous variables

The experimenter effect is a term used to describe subtle cues or signals from an experimenter that affect the performance of participants in studies. The cues may be unconscious nonverbal cues, such as muscular tension or gestures. They may be vocal cues, such as tone of voice. Explain how to control extraneous variables

Mini Plenary “Sort it out” Explain how to control extraneous variables DefinitionThe EV they attempt to overcome Single blind Double blind Experimental realism Standardised procedures counterbalancing

Variables “Carrying more bags or sugar makes you run slower”. Extraneous and confounding variables Anything other than the IV that may influence the DV is an extraneous variable. We need to control these. If the dependent variable is influenced then the extraneous variable has become the confounding variable

Aims & Hypothesis I can Distinguish between directional & non Directional hypotheses Construct an operationalised hypothesis

Aims & Hypotheses Aims: An aim is a general statement of why the study is being carried out. Hypotheses: In psychology a hypothesis is: A clear statement A prediction Testable Formulated at the beginning of the research process A hypothesis to test the idea might be: Ps will correctly recall more words in a memory test after learning a list of words by image-linking than Ps who learn the same words via simple rehearsal. Distinguish between directional & non Directional hypotheses Construct an operationalised hypothesis

Hypotheses Experimental Hypothesis: Used when using the experimental method Alternative Hypothesis: Used when not using an experimental method e.g questionnaire Null Hypothesis: A null hypothesis predicts that any differences or similarities between the sets of results in an experiment are due to chance alone.

Spot the difference between the following 2 examples of experimental hypotheses: 1. There will be a difference in the reaction times between p’s who have drunk alcohol and p’s who have drunk water. 2. The reaction times of p’s who have drunk alcohol will be slower that the reaction times of those p’s who have drunk water. Distinguish between directional & non Directional hypotheses

Directional & Non Directional Hypotheses Mini Plenary: Directional & Non Directional? Distinguish between directional & non Directional hypotheses

Operationalising a hypothesis Hypotheses must be operationalised- this means writing it in a way that the IV & Dv are defined. To investigate the relationship between social class and intelligence To investigate the relationship between social class as defined by annual family income and intelligence as measured by performance on a standard IQ test TASK Construct and operationalised hypthesis for this “People remember more when they study in short bursts” Construct an operationalised hypothesis

To describe three types of experimental Methods and give strengths and weaknesses of them.

Laboratory experiments Field Experiments Natural Experiments Types of Experiment LAB V FIELD Come up with some strenghts and weaknesses of Lab & Field experiments

Well controlled. Permits us to study cause and effect. Confounding variables minimised. Can be replicated (copied/repeated)  Artificial or contrived.  Participants know they are being studied, which is likely to affect their behaviour. (demand characteristics)  Investigator may influence results.  The setting is not like real life – low in mundane realism.  it doesn’t represent real-life experiences e.g. trigrams to test memory  Low ecological validity Strengths and weaknesses of Lab Experiments Ethical Issues Deception Informed consent (is it truly voluntary?) Psychological harm

Permits us to study cause and effect. Less artificial so have higher ecological validity, (Easier to generalise from results.) Avoids some participant effects (when they are unaware of study)  Less control of extraneous variables.  More time consuming, so more expensive. Strengths and weaknesses of Field Experiments Ethical Issues Informed consent Difficulty debriefing Privacy

The IV has not been deliberately manipulated by the experimenter, so the situation is described as ‘natural’. This method used when there are IV’s that cannot be manipulated directly for ethical or practical reasons. Not true experiments – quasi experiments, because IV not changed deliberately to see effect on DV. Natural Experiments

Allows research where IV cannot be manipulated for ethical or practical reasons e.g. deprivation studies Enables psychologists to study ‘real’ problems e.g the effects of disaster on health – (increased mundane realism and ecological validity) Less chance of demand characteristics or experimenter bias interfering.  Cannot demonstrate causal relationships because IV not directly manipulated.  Many confounding variables (e.g allocation of participation to groups), threat to internal validity.  Can only be used where conditions vary naturally.  Participants may be aware of being studied. Strengths and weaknesses of Natural Experiments Ethical Issues Informed consent Confidentiality

Experimental Designs I can Name and evaluate three experimental designs

Name and evaluate 3 types of experimental designs.

Most simple experiments involve 2 conditions – these are 2 versions of the independent variable. e.g. Using words or pictures to learn a list of items. Condition 1 Words Condition 2 Pictures Name and evaluate three experimental designs

There are 3 different ways to carry out the experiment with participants. These are known as Experimental Designs.  Independent measures design  Repeated measures design  Matched pairs design Name and evaluate three experimental designs

Pictures Participants only take part in one condition of the experiment (2 separate groups) Words Name and evaluate three experimental designs

Pictures Participants take part in both conditions of the experiment (1 group) Words Name and evaluate three experimental designs

Participants are matched in each condition for characteristics that may have an effect on their performance. e.g. A memory test Name and evaluate three experimental designs

Experimental designs Aim: To see if music affects the ability to write the alphabet backwards. What type of experiment will you use? What will the IV be? What will the DV be? What problems are there with each of the experimental designs? How could we overcome the problems? Name and evaluate three experimental designs

I’m cleverer than her! The colour pink is so awesome... Name and evaluate three experimental designs

Cat Dog House They think I’ll remember pictures better than words I got bored the second time …

Counterbalancing In a repeated measures design there may be order effects. This is when they get bored or fatigued from doing a repetitive task. Or they get better in condition 2 because they have had practice. Counterbalancing- split the group in half, half do condition 1 first then condition 2. then the other half do 2 then 1. Name and evaluate three experimental designs

Name and evaluate 3 types of experimental designs.

Key Terms Counterbalancing Experimental design Independent groups Matched pairs design Order effects Random allocation Repeated measures design Single blind Demand characteristics Investigator effects Field experiment Natural experiment Independent variable Dependent variable Extraneous variable Confounding variable