Tom Coster – Psychology

Tag: research

  • Psychology vocabulary

    An often-neglected aspect of teaching IBDP Psychology helping students develop fluency with subject-specific terminology. Words like validity, reliability, etiology, synaptic gap, neurotransmitter, and operant conditioning aren’t just vocabulary, they’re the precise tools we use to communicate complex ideas about behavior.

    The assessment criteria make this explicit: ‘There is accurate and precise use of psychological terminology’ and ‘Psychological terminology relevant to the research methods is used effectively’. These aren’t minor criteria, they directly affect student grades in all assessment components. When students write about ‘proof’ instead of evidence, or ‘sadness’ instead of depression, they’re not just being imprecise; they’re failing to demonstrate the precise and accurate vocabulary that examiners expect.

    Teaching terminology effectively means more than providing definitions. Students must understand when and how to use these terms. Does this theory apply to all cultures or is it ‘culture-bound’? Is this a hormone or a neurotransmitter? Understanding these distinctions demonstrates genuine psychological literacy, not just memorization.

    The payoff extends beyond exam scores. Students who master the subject’s vocabulary think more precisely about behavior, communicate more effectively in their internal assessment and extended essays, and develop the academic foundation necessary for university level psychology study.

    IB Diploma Psychology – The Glossary of Psychology Vocabulary (by Tom Coster) is an essential companion for every IB Diploma Psychology student, providing a clear and concise collection of key terms and concepts tailored to the IB Psychology syllabus.

    Designed to support your journey into the field, this glossary will enhance your understanding of human thought, emotion, and behavior, while helping you master the specialized vocabulary required for academic success and real-world application.

  • Causality and the experimental method

    At the heart of psychology lies a beautifully simple question: What causes what? The experimental method gives us the clearest path to answering this question, and its elegance lies in its straightforward logic.

    Causality is the relationship between cause and effect. When we say “X causes Y,” we mean that changes in X directly produce changes in Y. In psychology, establishing causality allows us to move beyond mere correlation and understand the mechanisms behind behavior.

    The key requirement for causality is that we must demonstrate that one variable directly produces a change in another variable.

    The experimental method is powerful precisely because of its simple logic. The basic formula involves three steps. First, change one thing, which is the Independent Variable or IV. Second, keep everything else the same by controlling all other variables. Third, measure what happens by observing changes in the Dependent Variable or DV.

    The beautiful conclusion follows naturally. If the DV changes, and we’ve controlled everything else, then the change in the IV must have caused the change in the DV. That’s it. That’s the entire logic.

    Teaching Tip 1: Start with the Logic: Before diving into terminology, help students grasp the fundamental reasoning. If I want to know whether caffeine improves memory, I need to change only the caffeine and see what happens to memory. If I change multiple things at once, I can’t know which one caused the effect.

    Teaching Tip 2: Emphasize Control: The power of the experimental method isn’t in what we change, it’s in what we don’t change. Every variable we control strengthens our claim of causality.

    Teaching Tip 3: Connect to Real Research: When teaching studies like Loftus and Palmer on leading questions and memory, or Bandura’s Bobo doll experiment on observational learning and aggression, highlight the beautiful simplicity. Identify the IV, which is the variable the researcher manipulated. Identify the DV, which is what they measured. Note the controls, which is everything they kept the same. Then draw the conclusion: because everything else was controlled, the IV caused the change in the DV.

    The Three Essential Components: Help students remember these three pillars. First is manipulation, where the researcher deliberately changes the IV. Second is control, where all other variables are kept constant. Third is measurement, where the DV is carefully observed and recorded.

    When all three are present, we can claim causality. When any are missing, we cannot.

    Some students believe that correlation shows causation. This is incorrect. Only the experimental method establishes causality because only experiments control for alternative explanations.

    Others think that any study with numbers shows causation. This is also incorrect. Surveys and correlational studies provide valuable data but cannot establish cause and effect.

    Some confuse control with control group. This is partially correct. Control means keeping variables constant and may include a control group for comparison.

    Making It Stick: Use this simple framework when analyzing any study. (i) What did they change? That’s the IV. (ii) What did they measure? That’s the DV. (iii) What did they control? Those are the other variables. (iv.) Can we claim causation? Only if it’s a true experiment.

    The experimental method’s beauty lies in its logical simplicity. Change one variable, control all others, measure the outcome. If the outcome changes, you’ve found your cause. This simple logic is psychology’s most powerful tool for understanding the mechanisms of human behavior.

    Here’s a powerpoint presentation that you can use for teaching a lesson on the true and quasi experiment.

    True and Quasi Experiments in PsychologyDownload

  • Why Research Studies Still Matter in Teaching Psychology

    One of the quiet revolutions in teaching IB Psychology is this: our students no longer need to memorise outlines of 200 or more studies, each with two strengths and two limitations. That’s worth celebrating. It makes our subject lighter, more engaging, and far more relevant. Students can now focus on developing critical thinking, connecting concepts, and applying their knowledge rather than playing flashcard games with endless lists of studies.

    But let’s not forget: research is the scientific foundation of psychology.

    Would you teach ethics in psychology without telling your students about Little Albert and the white rat, Zimbardo’s appalling Stanford Prison Study, or Milgram’s not-so-appalling obedience experiments? Of course not. These are the stories that not only illustrate concepts but also bring to life the ethical debates that shape our subject.

    Would we introduce social identity theory without Sherif’s Robbers Cave study? Could we possibly explain observational learning without Albert Bandura’s endlessly punched Bobo doll? And when we turn to methods, what better way to anchor quasi-experiments and neuroplasticity than Eleanor Maguire’s London taxi drivers, or to illuminate the case study method than Henri Molaison, whose memory loss is legendary?

    The point is simple: research gives psychology its credibility.

    Yes, assessment criteria don’t explicitly require studies by name. Students aren’t graded on whether they remember that it was 22 boys in Sherif’s camp or 72 children in Bandura’s playroom. But to teach any of the IB Psychology concepts with integrity, we must draw upon the research that produced them. Without robust studies and their conclusions, our discipline risks floating away into abstraction, detached from the science that grounds it.

    So let’s celebrate freedom from rote memorisation, but let’s also celebrate the research itself. Studies are not an add-on; they are the very evidence that makes psychology worth studying.

  • Moving from research studies to real-world examples

    One of the most noticeable shifts in the new course is the emphasis in assessment on examples rather than memorised research studies. In Paper 1, Section A, those short 10-minute questions are marked against just two descriptors:

    1. The response demonstrates detailed knowledge relevant to the question.
    2. The example is relevant and explained.

    Note that word — example — not research study. In fact, the only time assessment criteria explicitly require reference to a research study is when it’s mentioned in the question itself (Paper 2, Section B).

    Over the years, I’ve enjoyed teaching the finer details of Henri Molaison (Scoville & Milner), Baby Albert (Watson & Rayner), Milgram, Odden & Rochat, Caspi et al… These classic studies are fascinating and still worth knowing, but the new Guide is clear: it’s example, not studies.

    Research will always be a valid and robust part of a Psychology course.

    Students often memorise outlines of these studies and then regurgitate them in the exam. That’s not the same as demonstrating real knowledge and understanding.

    This isn’t to say we should stop teaching research studies — I certainly won’t. I’ll continue to speak lovingly of the Dunedin Study, the HM case, and several others. But students and I won’t be getting anxious about memorising the number of participants in the HM case study (eh hem, that’s a little psychology research joke there), or the nationality of Dunedin Study participants, or the socioeconomic status of Kahneman and Tversky’s samples. We can still use research studies — and we should — but students won’t have to memorise the details.

    The real focus is transfer of knowledge. Taking Social Identity Theory and applying it to a bullying case in a school or an international conflict. Using Social Learning Theory to describe how a public health campaign could reduce teenage alcohol consumption. Even if the example is fictional, applying the theory to a fresh, unseen situation shows depth of understanding far better than rattling off participant numbers and procedure details.

    This shift isn’t about discarding research — it’s about using it. The research is the foundation. But in assessment, it’s the bridge from theory to application that earns top marks. And that’s a far better reflection of what it means to understand psychology.

    Discuss the role of Social Identity Theory in explaining a conflict.