Lesson 1 Experimental Basics PDF

Research Methods 1: Laboratory Experiments 1. What is an ‘Experiment’? 2. What is an Independent Variable 3. What is a Dependent Variable 4. What are Confounding (Extraneous Variables) 5. What are Controls 6. Experimental Design Refresher: What is Psychology? Psychology is th...

Research Methods 1: Laboratory Experiments 1. What is an ‘Experiment’? 2. What is an Independent Variable 3. What is a Dependent Variable 4. What are Confounding (Extraneous Variables) 5. What are Controls 6. Experimental Design Refresher: What is Psychology? Psychology is the scientific study of the mind and behaviour. How do Psychologists come to know information about the Mind & Behaviour? Psychological (Scientific) Research What types of research will a Psychologist conduct? Psychologists use a mixture of these methods to discover new information, this approach is called TRIANGULATION (Laboratory) Experiments Case Studies Correlational Studies Interviews Questionnaires Observations  Lesson 1: Psychological Experiments What is an Experiment? An investigation looking to establish a cause-and-effect relationship  Key Vocab - Laboratory Experiment – Copy! A laboratory experiment is an experiment conducted under highly controlled conditions (not necessarily a laboratory), where accurate measurements are possible. The researcher decides where the experiment will take place, at what time, with which participants, in what circumstances and using a standardized procedure. From Year 2 Science: Fair CowsTest- Change one thing (independent variable) Moo - Measure something (dependent variable) Softly - Keep everything else the Same (controlled variable)  Change 1 thing (IV) e.g. Drug vs No Drugs Measure the same outcome (DV) e.g. Performance on task Keep everything else the same e.g. all participants do task at same COWS MOO time / same Independent (Cows) & Dependent (Moo) The researcher examines the what effect the independent variable will have on the dependent variable Key Definitions: Copy Down The Independent Variable (IV) is variable researchers choose to manipulate. It represents the different conditions of the experiment The Dependent Variable (DV) is what researchers choose to measure. (We hope the change in the IV will be seen in the DV) If all things are equal in the experiment, then the observed/measured change in the dependent variable MUST be CAUSED by the change of the independent variable What if things are not equal? Is it hard to keep things equal in Psychology Let’s create an example but first… Does eating sugar before an exam affect results? The independent variable is ‘eating sugar’ – Why? It has two ‘levels’ (it can have more) Participant does not eat sugar (sometimes the control condition) Participant does eat sugar (sometimes the experimental condition) The dependent variable is the ‘exam result’ – Why? Let’s assume the result - the participants who eat sugar do better on average on the exam Now if all things are EQUAL then the change in measured in the dependent variable must be caused by the change in the independent variable. – Why? Therefore we can conclude...? Cause and Effect! – Here are some examples Create your own Research Question of the following format: Does X affect Y? Then create the following flowchart for your Question __________________________  Design a simple experiment (feel free to be unethical???) Results: Participants:  Draw this Flow chart into Length of Study: your books Label: o Independent Variable o Dependent Variable  Fill out your predictions of the results _______________________ Next Write an Aim and a Hypothesis What are these? What is the difference? OOOoooOOOooo __________________________ Key Definitions: Aim: The Purpose Results: of the Study Participants: Length of Study: Hypothesis: A Prediction about the Findings of the Study before the _______________________ Study is Run But what if all things aren’t equal…? (Softly…)  o These are variables that can affect the relationship between the IV and the DV, they can therefore affect the outcome of the experiment, but they are Key Definitions not the variables of interest. For example: o Returning to our sugar experiment, what if the students who take (Copy Down): the sugar are already getting higher grades on average? o What if the students in the different conditions take the exam at different times? Extraneous Variables o What if the students think the sugar will have an effect, so a placebo effect occurs instead? o Bonus: What is a Placebo Effect? Key Definitions (Copy o KEY Definitions Some Extraneous Variables can be subclassified as Down): Individual & o Participant Variables: Variables Situational Variables that participants bring to the study e.g. prejudices, gender, previous experience with a task, level of intelligence o Situational Variables: Variables that the situation can bring to the study that will affect the DV e.g. Temperature, Noise from the outside, Weather… o Note (maybe controversial) time (of day) in past papers has not been accepted as a situational variable.  Create the following chart: __________________________ Label potential Participants: Results: extraneous Length of Study: variables on to your flowchart _______________________ What could be the solution? Controlling the Experiment We do not want any other variables affecting the DV. Researchers will find ways to control variables that could do this. Key Definitions (Copy Down): Standardisation: A standardised procedure is one where all participants follow the same order of events, and all aspects of the study (e.g. instructions or materials used) are standardised (the same). The more standardised the more likely another researcher could replicate it to test for reliability Controls: Controlling variables is done to strengthen the cause-effect-relationship. E.g. remove an extraneous variable. Standardising adds to this strengthening as it does eliminate some variables, but this is a separate concept. o Strict controls also makes the experiment unnatural o Therefore, the effect, while found in the experiment, may not be observed in real life o Because real life HAS ‘extraneous variables’ (This is called ecological validity more on this later…)  Create the following chart: __________________________ Label potential Participants: Results: solutions Length of Study: (controls & standardisations) _______________________  It gets worse! Final definition: __________________________ Uncontrolled Variables: These are variables that Participants: Results: cannot be Length of Study: controlled by the researcher e.g. forces of nature Task: Write down some examples… _______________________  Create the folowing chart: __________________________ Redesign your Results: experiment to be Participants: a Repeated Length of Study: Measure How would you COUNTERBALANC E IT??? _______________________ Homework Read through the following sections of the textbook (on GC) Page 1 & 2 – Stop when you hit the section called ‘Self- Reports’ Add to your notes and write down the three Experimental Designs and their Strengths and Weaknesses Page 5 & 6 - read The Section Called ‘Methodological Concepts’ and stop when you get to the section called ‘Types of Data’ Add to your notes on these topics  Experimental Design Exam tip – the phrase ‘experimental design’ for our exam board specifically refers to this… Task: Discuss with your partner what would be the best Experimental design. Choose one, justify it, redesign your experiment accordingly.  When you are choosing participants what do you want? What are you looking for as a researcher? A Representative Sample Representative of who or what? Can we have a go at this? (Paper 2 Section A) KEY DEFINITION  Lesson 2: Choosing your Participants – The Sample & Sampling VOLUNTEER! – Who Can We Generalise To? Who Could We Generalise To? Who Could We Generalise To? Who Could We Generalise To? Who Could We Generalise To? Sometimes it will depend on what we are studying, more cultural phenomenon will be harder to generalise than biological  ALL of one type of person Your participants Obvious Sex (samples) limit who issues… Gender Age you can generalise your study to. You can Socioeconomic status always argue Education level something may be true in the general Part of the country population, however Country the more Race representative your … and so on sample, the easier this Why might these will be… affect who we can generalise results to? How many people do you want? As many as you can within reason. It also depends on what you are studying. Biological psychology is more reliable than social psychology. Therefore, you can study the visual cortex with fewer participants and make generalisable conclusions the than bystander effect. How do we choose our Participants? (Sampling)  In your group you will have one of the following: Opportunity Self Selected (volunteer) Read section Random 1.8 in your Write down the: Explanation of… textbook (pp. Strengths Weaknesses 23 – 25) When you think it would be appropriate to use this type of sampling We will then share as a class! – WRITE DOWN the ones you did not study! Individually: Read the ‘Research Methods in Practice’ section & ‘Reflections section on page 26, and complete the activity/answer the questions.  The Popula Sometimes this may be the tion ‘General Population’, sometimes you may want to you are study 15-25 males from low SES backgrounds, people with schizophrenia etc… Studyi ng Paper 2 Section A Paper 2 Section B