Experimental Psychology and the Scientific Method PDF

CHAPTER 1 THE NEED FOR SCIENTIFIC METHODOLOGY - In our daily lives, we all collect and use psychological data EXPERIMENTAL PSYCHOLOGY AND...

CHAPTER 1 THE NEED FOR SCIENTIFIC METHODOLOGY - In our daily lives, we all collect and use psychological data EXPERIMENTAL PSYCHOLOGY AND to understand the behavior of others – and to guide our own THE SCIENTIFIC METHOD behavior as well o This kind of everyday, nonscientific data gathering OBJECTIVES that shapes our expectations and beliefs – and directs 1. Understand why we rely on scientific methods rather than our behavior towards others – is called common sense to explain behavior commonsense psychology (Heider, 1958) 2. Learn the principles of the scientific method 3. Learn the basic tools of psychological research - Commonsense psychology seems to work well enough for 4. Understand how “cause and effect” is established by us – most of the time experimentation o At other times, nonscientific data gathering can leave us up in the air INTRODUCTION o An understanding of commonsense psychology might - Psychology is the science of behavior not help with all dilemmas – but it will make you a o As psychologists, we take a scientific approach to better psychological scientist understanding behavior – and our knowledge about o This is because it demonstrates the need for a more psychological processes is based on scientific scientific approach to understanding and predicting evidence accumulated through research human behavior o As scientists, we rely on scientific methods when we conduct psychological research – such as: - As commonsense psychologists, we find that our ability to § Specifying the conditions under which we make gather data in a systematic and impartial way is constrained observations by two important factors – the sources of information, and § Observing in systematic manners our strategies for inference § Accepting or rejecting alternative explanations of o Commonsense beliefs about behavior are derived behaviors on the basis of what we observe from data we collect from our own experience – and o Research about psychological processes underlying what we have learned from others behavior, then, is known as psychological science o The data we collect in our everyday lives are generated from a very small sample of behavior – so - The word science comes from the Latin word scientia – conclusions drawn from them are subject to a number which simply means knowledge of biases that limit their accuracy & usefulness o As the word is used today, however, it has two o Often, our sources of commonsense beliefs are meanings – content and process unreliable – and explanations/predictions derived from § The content of science is what we know – such them imperfect as the facts we learn in psychology or chemistry o Our language is filled with conflicting, commonsense § The process of science is how we know – the adages – and this kind of psychology does not help us systematic ways in which we gather data, note know which one to use or believe in relationships, and offer explanations - Nonscientific Sources of Data - Explaining the process of psychological science is the o Often, the data we gather as commonsense principal aim of this course – alongside the basic tactics psychologists come from sources that seem credible employed in psychological research and trustworthy – friends, relatives, people in o Methodology pertains to the scientific techniques authority, people we admire, reports from media, used to collect and evaluate psychological data books we’ve read, etc o Data pertains to the facts and figures gathered and § In reality, these sources are not always very conveyed throughout research studies good ones for obtaining valid information § Nonetheless, psychological information – - All areas of psychology rely on scientific research methods especially those offered by people we like, o Data may be collected in controlled laboratory respect, or admire – is typically accepted without conditions, to obtain the most precise information question o Data may also be observed and recorded in natural § This is because we rarely, if ever, test them. settings – or the contexts in which they typically occur Once we believe we know something, we tend to o Data may also be gathered via test administration – or overlook instances that might disconfirm our by observing personality functioning in real time beliefs – and instead seek for confirmatory o Regardless if data comes from laboratory instances of behavior experiments, real-world settings, or therapy sessions § This is called confirmation bias – all psychologists use scientific criteria to evaluate it  o It is also unlikely that anyone can completely avoid - Falsely assuming that specific behaviors are assimilating some myths, superstitions, and pop associated with certain individuals or psychology explanations for behavior instances Stereotyping - Related to trait explanations, knowing some o Research shows that we are more likely to believe detail about an individual may influence us to information if it comes from certain types of individuals believe certain things about them § Those who are popular - Similar to those who believe that the full § Those who are attractive moon influences psychotic behavior, § Those high in status stereotypical expectations can lead us to § Those with perceived expertise seek confirmatory instances of behavior § Those who appear confident - Misusing data to estimate the true probabilities of events – based on prior Gambler’s Fallacy o Other people are not our only source of data about experience or perceived outcomes psychological processes - When individuals see a slot machine has not § We gather information from our own paid off in a long time, there is a tendency to observations, and interactions with others – then believe that it is overdue for payout draw conclusions from them - In reality, it makes no difference whether the § Frequently, we use our beliefs and feelings a to machine paid off recently or not – unless the explain behavior – both our own, and others too machine itself is rigged § Such processes are not always conscious – as - Predictions, guesses, and explanations tend confidenc we are often unaware of factors that influence to feel much more correct than they actually e bias Over- our attitudes and behaviors are – based on the amount of data we have available (regardless if it is accurate or not) o Though we frequently use data from our own experiences to come up with commonsense assumptions about cause and effect – it is important - These and many other inferential biases exist in human we don’t rely on it, as we would frequently be wrong information processing o They are believed to be the brain’s way of coping with - Nonscientific Inference immense volumes of information - One of the first and most important kinds of o They are shortcuts, allow us to function well enough data we collect about others are in the traits (most of the time) – but they are not always accurate we assign to them o If we want to rely on our conclusions and use them as - There is a strong bias to overlook situational general principles to predict behavior across many data, in favor of data that substantiate trait settings and conditions – we need to proceed more explanations (e.g., someone fashionable is systematically, and objectively (scientifically) vain) - We tend to miss or ignore information about - The steps scientists take to gather and verify information, the situation itself (e.g., someone fashionable answer questions, explain relationships, and communicate is the daughter of a designer) information to others is the scientific method Trait Explanations - Our abilities to make accurate predictions about someone’s traits increases with the THE CHARACTERISTICS OF MODERN SCIENCE length of acquaintanceship - The Scientific Mentality (Whitehead) - Perceiving others by traits can be useful for o The psychologist’s goal of prediction rests on a simple predicting their behavior, but it can also lead (but important) assumption – behavior must follow a to overestimations of the likelihood they will natural order; therefore, it can be predicted act in trait-consistent ways o Faith in an organized universe is essential to science - This bias is hard to overcome, even with – because if no inherent order existed, there would be training no point in looking for one; nor any need to develop - Though controversy exists regarding whether methods for doing so traits or situations are better predictors of o Researchers share the belief that there are specifiable behavior – traits are believed to be more (although not necessarily simple nor obvious) causes useful for predicting behavior in the long- for the way people behave (determinism) – and these term; while situations might be better for causes can be discovered through research momentary behaviors - Gathering Empirical Data - Good Thinking o Whitehead – a philosopher of science who traced the o A central feature of the scientific method is good development of science in his book Science and the thinking – as the collection and interpretation of data Modern World (1925) – tied the beginnings of modern should be systematic, objective, and rational science to the Greek philosopher Aristotle § The scientist avoids letting private beliefs or o Like contemporary scientists, Aristotle assumed that expectations influence investigations order exists in the universe – and such order can be § Good thinking entails openness to new ideas – described in a systematic way through empirical data even if they contradict prior beliefs or attitudes (i.e., data that can be observed or experienced) § Good thinking follows the rules of logic – wherein o Such data can be established through the systematic conclusions must follow from the data, observation and careful classification of naturally regardless if they align with our predictions or not occurring events o Another important aspect of empirical data is that they o The principle of parsimony is crucial to good thinking can be verified or disproved through investigation § Sometimes called Occam’s razor, which is o Though gathering empirical data in a systematic and founded on the basic premise – entities should orderly manner is preferable to commonsense data – not be multiplied without necessity it does not guarantee accuracy or truth § It is the problem-solving principle of searching for explanations w/ the smallest set of elements - Seeking General Principles What Occam had in mind was simplicity, o Modern scientists go beyond cataloging observations precision, and clarity of thought to proposing general principles that explain them When two explanations are equally o We could observe endless pieces of data – adding to defensible, the simplest one is preferred the content of science – but our observations would be of limited use without principles to structure them - Self-Correction o When principles have generality to apply to all o Modern scientists accept the uncertainty of their own situations, then they are called LAWS conclusions – the content of science changes as we § Laws consist of statements generally expressed acquire new information; and old information must be as equations – with few variables that have reevaluated in light of new facts overwhelming empirical support § Changes in scientific explanations are an § They explain WHAT happened in a condition extremely important part of scientific progress § Experience favors a weight-of-evidence o Typically, we do not have enough information to state approach – the more evidence that accumulates a general law – but we advance understanding by to support a particular theory, the more devising and testing an interim explanation, commonly confidence we have that the theory is correct called a THEORY § Theories are sets of related statements used to o Science is self-correcting – as scientific explanations explain and predict phenomena and theories are challenged, revised, or replaced § They explain WHY or HOW things happened § They integrate diverse data, explain behavior, - Publicizing Results and predict new instances of behavior o Because of its dynamic nature, modern science has become a highly public activity o Testing predictions stemming from a theory has been § Scientists meet frequently through professional a cornerstone of psychological science – which is and special interest groups – and attend done through constructing HYPOTHESES professional conferences to exchange § Hypotheses are assumptions that are proposed information about current work for the sake of argument – in order for them to § The number of scientific papers published each be tested for potential truth year is growing, and new journals are constantly being added to specialized disciplines o Theories can explain many, but not all instances of § This continuous exchange of information is vital behavior. The more a theory explains, the better it is to the scientific process § Science progresses only through progressively better theories (Popper, 1963) o It would do little good for scientists to work in isolation § Old theories are replaced by new theories § The opportunity to incorporate the most recent findings of others would be missed o Laws are seldom determined outside the physical § There would be a lot of wasted effort as sciences – so the behavioral sciences largely researchers duplicated both failures and progress by developing better and better theories successes alike - Replication THE SCIENTIFIC METHOD: TOOLS OF PSYCHOLOGICAL o Scientists must be able to repeat procedures – and SCIENCE get the same results again – if we have gathered data - Systematic noting and recording of events objectively, systematically, and rationally - Only events that are observable can be studied o Findings that are obtainable by only one researcher scientifically have very limited scientific value - Many behaviors are observable – like smoking, smiling, talking – but what about internal processes THE OBJECTIVES OF PSYCHOLOGICAL SCIENCE like feeling, thinking, problem solving? Observation - Initial step towards understanding any phenomenon - In order to explore these areas, we just need to - Refers to the systematic and unbiased account of define them in the form of observable signs – time it Description observed characteristics of behaviors or situations takes to solve a problem; responses to a mood - Examples of descriptive research designs are case questionnaire; amplitude of one’s electrodermal studies (outside observer records behaviors and/or responses experiences of a single individual) and field studies - Within the scientific framework, observations must (observational studies of groups of beings in real-life) be made systematically (consistently across - Refers to the capacity for knowing in advance, when observations) and objectively (fairly across certain behaviors would be expected to occur – to be observers) able to predict them ahead of time; as we have - Assignment of numerical values to objects or events identified other conditions with which the behaviors or their characteristics – accdg. to conventional rules are linked or associated Prediction - Correlational designs are commonly used to help - In research, we assign numbers to different sizes, predict behavior – as statistical relationships are quantities, or qualities of observed phenomena sought after between different events, behaviors, or - Rather than relying on global impressions, we use Measurement experiences standardized units, agreed-upon conventions that - Quasi-experimental designs are also used – as define such measures systematic differences among groups of people could - As standards for behavior are not always as clear- also be examined for prediction of behavior cut, we can determine them by the context of our - When we explain a behavior, we also understand what investigation – behavior in a situation, reactions to causes it to occur the situation, evaluations of the situation, etc. - Explanation includes knowledge of the conditions that - In experiments, we are interested in comparing reliably reproduce the occurrence of behavior behavior of participants who have been exposed to - To explain behavior, we have to use experimental different sets of conditions designs – in which we systematically manipulate - Process undertaken to test a hypothesis that Explanation aspects of the setting, with the intention of producing particular behavioral events will occur reliably in specific behaviors certain, specifiable situations - At the same time, we control for other factors that - Here, we systematically manipulate aspects of a might influence the behavior during the experiment setting to verify our predictions about observable - Only the results of true experiments allow inferences behavior under specific conditions to be drawn regarding cause-and-effect - To conduct an experiment, our prediction must be - Many times, however, true experiments are not testable. This necessitates three requirements: Experimentation feasible (nor desirable) – hence, non-experimental or o We must have procedures for manipulating the quasi-experimental methods are preferred setting - Refers to the application of what has been learned about behavior o The predicted outcome must be observable - Once a behavior has been explained through o We must be able to measure the outcome experimentation, it may be possible to use that - In addition to this, experiments must also be knowledge to effect change or improve behavior objective. We do not bias our results by setting up situations in which our predictions will automatically Control - Control is rarely the intent of experimentation, but some research is conducted with the intent of be confirmed producing behavioral change – alongside increasing - Finally, experiments must be ethical. In the same knowledge way we do not stack the deck in our favor by giving - Across experiments, the intention is two-fold – (1) subtle cues to respond desirably – we also do not testing the effects of specific conditions; and (2) carry out unethical tasks for the sake of discovery changing the behavior itself (i.e., controlling it) - Research designed to solve real-world problems is called APPLIED RESEARCH. In contrast, those designed to test theories or explain phenomena is BASIC RESEARCH SCIENTIFIC EXPLANATION IN PSYCHOLOGICAL SCIENCE - Establishing Cause and Effect - Identifying Antecedent Conditions o The greatest value of the psychology experiment is o In science, explanation means specifying the that – within the experiment, we can infer a cause- antecedent conditions of an event or behavior and-effect relationship between the antecedent o Antecedent conditions are the circumstances that conditions (IVs) and subject behaviors (DVs) come before the event or behavior we wish to explain § If XYZ set of antecedents always leads to a o If we can identify all antecedents of a behavior, we can particular behavior, whereas other treatments do explain that behavior in the following way – not – we can infer that XYZ causes the behavior § When XYZ is the set of antecedent conditions, § Though many different research methods can be the outcome is a particular behavior used to study behavior, only a true experiment § If the XYZ set of antecedents occurs again, we allows us to make statements of causality expect the same outcome o The type of cause-and-effect relationship established - Comparing Treatment Conditions through experiments is called a temporal o In psychology, it would be virtually impossible to relationship – because a time difference occurs in it identify all the antecedents that affect the behavior of § The treatment conditions come before the research participants at a particular time behavior – or stated differently, the cause o Although we cannot identify all antecedent conditions, precedes the effect we can focus on particular antecedents that we § Differences in behavior are investigated after believe have an effect on behavior subjects are exposed – not before o In the psychology experiment, we create specific sets § If you observed differences before the of antecedent conditions called treatments treatments were implemented – you would need § This does not always mean that we do to look for another cause that preceded them something to “treat” participants (although it can) - Necessary versus Sufficient Conditions § It just means that we treat participants differently o As we seek cause-and-effect relationships in science when exposed to different antecedent conditions and psychology, we try to identify the conditions under o We compare treatment conditions so that we can test which events will occur – distinguishing between what our explanations of behaviors in systematic and is necessary (essential) and sufficient (contributive) scientific manners o The cause-and-effect relations of scientific research § Here, we compare effects of different antecedent commonly involve identifying sufficient conditions conditions on particular behavior/s § When we seek causes, we rarely seek § When we specify the antecedents – or treatment conditions that are both necessary and sufficient conditions – that lead to a behavior, we have § To do so would involve a search for the first or essentially explained its occurrence primary Cause (with a capital C) § Given the complexity of the universe, we would - The Psychology Experiment make slow progress in our search for order – if o It is a controlled procedure in which at least two we refuted to settle for anything less than causes different treatment conditions are applied to both necessary and sufficient participants (subjects) § Finding the Cause of a cause yields an even o Participants’ behaviors are then measured and more complicated question – the Cause’s Cause compared to test a hypothesis about the effects of those treatments on behavior FROM PSEUDOSCIENCE TO PSYCHOLOGICAL SCIENCE o Procedures in psychology experiments are carefully - Psychology as an experimental science did not emerge controlled – so that we can be sure we are measuring until the late 1800s what we intend to measure. This is done via: o Wilhelm Wundt is generally credited with being the § Random assignment of subjects to different first experimental psychologist – and the birth of treatment conditions psychological science is usually dated from the § Presenting a treatment condition in an identical opening of his laboratory in Leipzig, Germany (1879) manner to all subjects o There, Wundt employed the tools of the scientific § Keeping the environment, procedures, and method – observation, measurement, measurements constant for all participants experimentation – to study human sensory experience o As Wundt’s fame grew, students from all over the o A true experiment has four elements world came to Leipzig to work in his labs. One of his § Manipulation (of independent variables) first students was G. Stanley Hall § Control (of extraneous variables) o Hall went on to open the first psychology laboratory in § Randomization (of conditions) the United States in 1883, at John Hopkins University § Replication (of procedures) - Early academic psychology in the United States found its home in departments of philosophy – under the rubric of mental philosophy o Mental philosophy included the study of consciousness and mental processes – and was based on the premise that the human mind begins as a blank slate, gaining knowledge of the world through sensory experiences o Mental philosophers were primarily engaged in the study of the five senses – through introspection and observation of their own mental processes; and observing those of others o Mental philosophers were not practitioners of the scientific method – and were not much bothered by the fact that the human mind was both the observer, and the thing being observed - Despite methodological and philosophical differences, the mental philosophers and experimental psychologists found a common adversary – pop psychology o Pseudoscientific practices were very popular during the 1800s – phrenology (conformation of skull as indicative of mental faculties and character traits), physiognomy (judgement of character based on facial features or expressions), mesmerism (realigning bodily fluids thru magnets, electrodes, etc.), spiritualism (purported contact with ghosts and spirits of the dead via seances and various mediums) o Pseudoscience characterizes any field of study that gives the impression of being scientific – but has no true scientific basis; nor has been confirmed using the scientific method o The popularity of pseudoscientific psychology is alive and well today – in the guise of astrology, palmistry, fortune telling, numerology, and the like o Even within the field of psychotherapy, pseudoscientific practices exist – past life regression, reparenting, rebirthing, primal scream therapy, cathartic release, neurolinguistic reprogramming, eye movement desensitization, inner child therapy, alien abduction therapy