Starter – key words Experimental design – the way in which groups of participants are set up in an experiment Repeated Measures – participants take part in all parts of the study Independent Groups – separate groups of participants doing different parts of the study Matched Pairs - separate groups of participants doing different parts of the study but each participant is matched on certain characteristics. Extension – mini-white board lottery

Learning Objective Grade D/C - By the end of the lesson you should be able to define the three types of experimental designs Grade B/A – By the end of the lesson you should be able to explain one advantage for each experimental design.

Methods of Control, Data Analysis and Data Presentation In an experiment, researchers might want to know if one group of people are better at something than another group. They would do an experiment and collect a lot of numerical data – with a separate set of data from both groups. The way in which participants are assigned to groups is called experimental design and there are three different ways of doing this.

Consider this… In a study to see if caffeine (in coffee and tea) affects a person’s ability to play a computer game, how could we actually test this? We could have two separate groups with one drinking coffee before they play the computer game and the other group not drinking coffee before the task. From this we could determine who was better by comparing their results so it was important to put them into groups. What is the hypothesis, IV and DV here?

Your First Task: You will now carry out a ‘Marketplace’ activity. You will be in groups. You will receive information on one of the three ways that experimenters put participants into groups (called experimental design) You will create a poster in your groups with lots information on so that you can teach others about your design from it. One person from the group will then stay where they are so that they can teach others, while the rest will go around the room to look at the other ‘Stalls’. Your aim is to find out what all 3 designs are topics DON’T PANIC IF YOU DON’T KNOW WHAT SOME OF THE WORDS MEAN – YOU WILL BE LEARNING ABOUT THEM NEXT LESSON!!!!

What info to include on your table: What is the design called? A description of that design An advantage of that design A disadvantage of that design

The Rules: All of the group must be involved. By the end, everyone in your team should have a table of information completed on all 3 experimental designs. I will be picking people out to answer questions at the end based on any of the designs! Have Fun!

Independent Groups Here there are different participants in each group, each group is independent of each other. Participants should be put into the groups randomly so that all participants have an equal chance of getting put into each group. Advantage – It is quick and easy there are no order effects Disadvantage – Participants vary so there may be completely different participants in each group, making the group’s results hard to compare.

Repeated Measures Every participant goes through both experiences, rather than having two separate groups of participants Disadvantage – Because the participants are taking part in both conditions this may allow them to guess the aim of the study so they may act as they think the experimenter wants them to act (demand characteristics). Advantage – No problems with comparing groups as there are no differences between participants.

Matched Pairs Participants are matched in pairs on the basis of characteristics relevant to the study e.g. age, gender or reading ability. One of each pair in then randomly put into either the experimental or control group. Twins are perfect for this design. Disadvantage – This can be time consuming trying to get a large number of matching participants. Advantage – Because participants only do one condition, they won’t guess the aim (demand characteristics) or get too tired (order effects)

Mini-Plenary Answer questions using the mini- white boards in teams. (8 minutes)

Your Next Task: Now, go back to your group and feedback what you have learnt – you must ALL have your table completed by the end of the lesson. DON’T PANIC IF YOU DON’T KNOW WHAT SOME OF THE WORDS MEAN – YOU WILL BE LEARNING ABOUT THEM NEXT LESSON!!!!

Self-Reflection of Learning Objectives Today we have looked at …………………………………… I have found it ………………………………………………… The keywords that I have used today are……………… One area I need to practice is……………………………… What was the aim of the lesson? What do you need more help with? What did you learn today? Did anyone or anything help you move on to learn something new? What can you do now that you couldn’t do before? What did you find difficult? What are you most pleased with? To do better in this topic I need to ….? Grade D/C - By the end of the lesson you should be able to define the three types of experimental designs Grade B/A – By the end of the lesson you should be able to explain one advantage for each experimental design