The Scientific Method, 3 Main Theories:How is science better than common sense, intuition or personal experiences?In this course, we will learn about the ways and means of developmental research; the types ofstudies and limitations; and how you get published.Without research, we rely on our own experiences, intuitions and beliefs. The problem is thatthese things are often wrong.The scientific method is used to gather facts via observation (unbiased observation), generatetheories (aka predictions), and test our predictions in an experiment.A theory will always do four things: describe, organize, predict and explain behaviorThe scientific method is nice because its ideas are “falsifiable,” meaning they can be provenwrong.The main question we ask in this course is What makes kids act the way they do?There are three broad categories of explanations:● The physical category encompasses hormones, genes, biology, sleep, nutrition, etc.● The cognitive category encompasses language, thought patterns, etc.● The social category encompasses friends, family, culture, etc.Your theory (your category of explanation) will determine your intervention. Physical results inbetter drugs, cognitive results in better education/therapy and social results in better socialsystems.All theories are necessarily incomplete. Imperfect at best, wrong at worst. But they are alwaysimproving based on new evidence, and they all build on one-anotherThe confirmation bias refers to looking at facts that fit your view, and it’s one of the biggestproblems with theories. To combat it, meta-analysis studies multiple existing studies to findcommonalities and see if it (or other forms of bias) were at playTypes of Studies: Experiments, CorrelationalThe two main methods of scientific research across all fields are correlation studies (which areabout the relationships between variables) and experimental studies (which are all about themanipulation of variables)Correlations are usually a static picture, rarely 100%, and don’t imply causation. Correlationsare either positive (as one variable increases, so does the other) or negative (as oneincreases, the other decreases).Correlations are measured on a scale from 1 to -1. If it is 1, it is perfectly positively correlated. Ifit is -1, it is perfectly negatively correlated. If it is 0, there is no correlation whatsoever● Anything stronger than 0.5 or -0.5 is considered large.Correlations are tricky because if we find a correlation between A and B, that could mean a fewthings. A could cause B; B could cause A; or A and B could be caused by something else.Experiments, on the other hand, involve manipulating an independent variable to see if thedependent variable changes. (The confounding variable is something that might influenceboth variables, so we try to control it to make sure it doesn’t interfere.)We do this to test a hypothesis. Testing a hypothesis does test causation.Even if the hypothesis is right, it might only be a spurious result (due to luck or unknowncircumstances). To avoid these, we often blind the test in some way to ensure anonymity,objectivity and accuracy.If we operationalize variables, that means we are taking abstract psychological constructs andmaking them logical. For example, taking the broad idea of “intelligence” and operationalizing itby making it an IQ test. This is an important part of experiments.There are two main ways we can tackle experiments:● Within-subjects is a form of experiment where the same person is experimented onmultiple times● Between-subjects is where different people experience different thingField Experiments are a specific type of experiment that are done “in the field” as opposed to alab, which is difficult because they often have confounding variables that we can’t control.Lab Experiments are done in a lab, which are more controlled but might be less accurate.____The two main designs to acquire lots of developmental data in a “developmental study” is toeither do a longitudinal design or a cross-sectional design.● The former is a within-subject that looks at how one person changes over time.● The latter is a between-subject that looks at different children at different ages.The latter is more convenient but can lead to its own problems because the people beingcompared grew up in different times.The former tends to be more powerful, but it has a few problems:● It can lead to selective attrition: when people try to do bad to drop out of a test becausethey’re exhausted and sick of it.● Longitudinal studies also have the problems of cohort effects, which are conclusionsthat might not hold because it’s from another generation● They are very expensiveTypes of Studies: Observation, Self-Report, Psy TestIn addition to those two main types of studies (correlational and experimental), as well as theexperimental subtypes (within-subject and between-subject), there are a few other ways wegather data:1. Observational where we study childrena. Naturalistic Observation is where we study children naturallyb. Structured Observation is where we study children in a structured environment2. Self-reports of particular behavior, but they are not always accurate.3. Psychological Tests are focused on taking abstract ideas like memory, intelligence, etc.and making them more digestible and useful to understand. This process is known asoperationalizing4. Quasi-Experimental Design is a type of design where the people aren’t randomlyselected._______One of the biggest problems in all of these studies is to get reliable ways of getting data. Notest is better than its reliability! Reliability is just how likely subjects are to repeat their behavior.(For ex: the Rorschach test is infamously unreliable because it’s so subjective and so open tointerpretation.)Another big concern is validity: that this question/test/experiment measures what you want tomeasure._____Unfortunately, our study is only as good as the people.The population is the big group we care about, but the sample is who we actually measure.I mentioned meta-analysis above. In addition to eliminating biases, it can eliminate samplingerrors (discrepancies between sample and population).Stages of Life:Infancy is the first stage of life, lasting from birth to talking (1 year)Toddlerhood lasts from walking to school ageChildhood follows afterwards and stops before the teen yearsAdolescence encompasses the early teen years, and it ends with pubertyEarly