Lesson idea: Intro to the scientific method in psychology

tdixon Uncategorized 7 Comments

The scientific method is rather intuitive, so in one of my first lessons in the course I like to pose a problem to students and get them to see how they would solve it.

Here’s the problem: I’m trying to grow tomatoes in my garden and there are two types of fertilizer for sale. I want to know which one is the best to use, or is it better just to not use any. What would you do to find the answer to this question?


What you’ll find is that students will naturally design an experiment. They’ll come up with something like, “have three different tomato plants in different pots and give one each of the different fertilizers and leave one without any fertilizer and see what grows the best.”

This can then be used to introduce some basic terms like independent, dependent, extraneous and confounding variables.

Second task: Still working in groups, students can then discuss questions related to human behaviour and/or cognition that they’d be curious to find the answers to. Get them to pose a question and then try to figure out how they could go about finding the answer. This usually makes for some interesting class discussion. Finally, get students to compare their approach to the diagram below about the scientific method. How closely did their approach follow this format. Then get them to discuss the guiding question for the lesson. As usual, fast finishers can tackle the abstraction extension (all found on pg. 15).


The Scientific Method

 

Comments 7

  1. Mel,

    1st Unit!

    *Vanya Nario* *IB DP Coordinator/DP Psychology and TOK Teacher* The Beacon Academy Binan, Laguna Philippines

    On Thu, Jul 20, 2017 at 11:04 AM, IB Psychology wrote:

    > tdixon posted: “The scientific method is rather intuitive, so in one of my > first lessons in the course I like to pose a problem to students and get > them to see how they would solve it. Here’s the problem: I’m trying to grow > tomatoes in my garden and there are two types ” >

  2. Pingback: Lesson Idea: Introducing Researcher Bias – IB Psychology

  3. Hi Travis
    I’ve not come across any reference to confounding variables on the IB spec. Do you think we would need to distinguish between extraneous and confounding when teaching IB Psychology?
    Would you mind giving me examples of these two types of variables using your tomato plant example? I’ve tried finding out for myself, but can’t find an explanation for the difference between extraneous and confounding variables.
    Thanks
    Sarah

    1. Post
      Author

      Hi Sarah,
      The distinction is a bit tricky, and I wouldn’t get too hung up on it really. In a nutshell, my understanding is that an extraneous variable is a variable other than the IV that COULD have an effect on the DV, while a confounding variable is one that DID have an effect. So for example, amount of water given to the plants is an extraneous variable, so it needs to be kept constant. If one plant was in an area that got more water than the other, this would be a confounding variable. I think it’s important for students to grasp the idea of extraneous/confounding variables (you can lump them together, if you like) because if they don’t understand these then it’s difficult for them to fully grasp the role of controls in an experiment, I think. And also they’re essential for understanding the link between true experiments and causal relationships. So while they’re not essential by themselves, I think they are important building blocks that lay a foundation of understanding deeper ideas. Does that help?

      1. Thanks Travis, yes that helps. I’ve always taught extraneous variables, regardless of whether it’s clear if the variable could have or did affect the DV. Thanks for clearing that up! 🙂

        1. Post
          Author
          1. Well, it’s always good to be aware of these terms, especially if students come across them in their own research and need an explanation!

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