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 of studies and limitations and how you get published Without research we rely on our own experiences intuitions and beliefs The problem is that these things are often wrong The scientific method is used to gather facts via observation unbiased observation generate theories aka predictions and test our predictions in an experiment A theory will always do four things describe organize predict and explain behavior The scientific method is nice because its ideas are falsifiable meaning they can be proven wrong 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 in better drugs cognitive results in better education therapy and social results in better social systems All theories are necessarily incomplete Imperfect at best wrong at worst But they are always improving based on new evidence and they all build on one another The confirmation bias refers to looking at facts that fit your view and it s one of the biggest problems with theories To combat it meta analysis studies multiple existing studies to find commonalities and see if it or other forms of bias were at play Types of Studies Experiments Correlational The two main methods of scientific research across all fields are correlation studies which are about the relationships between variables and experimental studies which are all about the manipulation of variables Correlations are usually a static picture rarely 100 and don t imply causation Correlations are either positive as one variable increases so does the other or negative as one increases the other decreases Correlations are measured on a scale from 1 to 1 If it is 1 it is perfectly positively correlated If it 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 few things 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 the dependent variable changes The confounding variable is something that might influence both 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 unknown circumstances 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 and making them logical For example taking the broad idea of intelligence and operationalizing it by 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 on multiple times Between subjects is where different people experience different thing Field Experiments are a specific type of experiment that are done in the field as opposed to a lab 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 to either 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 being compared 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 because they re exhausted and sick of it Longitudinal studies also have the problems of cohort effects which are conclusions that might not hold because it s from another generation They are very expensive Types of Studies Observation Self Report Psy Test In addition to those two main types of studies correlational and experimental as well as the experimental subtypes within subject and between subject there are a few other ways we gather data 1 Observational where we study children a Naturalistic Observation is where we study children naturally b Structured Observation is where we study children in a structured environment 2 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 as operationalizing 4 Quasi Experimental Design is a type of design where the people aren t randomly selected One of the biggest problems in all of these studies is to get reliable ways of getting data No test 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 to interpretation Another big concern is validity that this question test experiment measures what you want to measure 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 sampling errors 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 age Childhood follows afterwards and stops before the teen years Adolescence encompasses the early teen years and it ends with puberty Early adulthood ages 16 25 Middle adulthood 30s 50s Late adulthood 55 The three types of development are physical development which concerns biology and growth cognitive development