Carlos Andres Rodriguez Herrera 1 31 23 Psychology 1100 Chapter 2 Research Methods 38 73 How exactly do we know stuff Dogmatism tendency for people to cling to their assumptions Laying down principles as true no other consideration for alternatives Trusted authority to answer questions the belief that accurate knowledge can be acquired through Empiricism observations Answer questions through examination The Scientific Method Scientific Method ideas and evidence a set of principles about the appropriate relationship between Logical framework for examining scientific questions Allows other researchers to replicate studies Steps 1 Ask question 2 Do background research 3 Construct hypothesis 4 Test with an experiment 5 Analyze results draw conclusions 6 If hypothesis is true report the results If it s false repeat step 3 Theory and Hypothesis Theory a hypothetical explanation of a natural phenomenon Hypothesis Ockham s Razor Rule of Parsimony simplest explanation is best usually the most a falsifiable prediction made by a theory Ideas about how and why things work the way Testable and falsifiable Hypothesis You must be able to say what we should or should not be able to observe if true accurate Theory Versus Hypothesis Theory A hypothetical explanation of natural phenomenon they do Never proven only supported People are Difficult to Study Complexity The human brain has billions of neurons all interacting to give rise to perceptions thoughts feelings and behaviors Variability Reactivity You are all individuals Hey People respond differently when they know they are being observed The Ohio State University 1 Carlos Andres Rodriguez Herrera 1 31 23 Measurement Defining the property Detecting the property Operational definition a description of a property in concrete measurable terms Measure a device that can detect the condition to which an operational definition refers Measuring happiness Electromyograph a device that measures muscle contraction of a person s skin Quality of Measures Validity the extent to which a measure and a property are conceptually related Is it measuring what we want it to Reliability whenever it is used to measure the same thing the tendency for a measure to produce the same measurement Is it consistent Necessity of being Conceptually Related An operational definition and the measurement used to detect the variable of interest must be related or valid Example measuring sadness Time spent crying each day vs Age of the person Which has more validity the ability of a measure to detect the concrete conditions specified in the Power operational definition Sometimes Measurement can be Influenced How do you act when you meet your partner s parents for the first time Demand characteristics those aspects of an observational setting that cause people to behave as they think they should How do we avoid this Naturalistic observation a technique for gathering information by unobtrusively observing people in their natural environment Alternatives to Naturalistic Observation Anonymous responses Measure behaviors that are not susceptible to demand Participants don t know behavior and demand aren t related Involuntary behaviors Physiological responses Taste test vs sweets control Blind participants True purpose isn t revealed Observer Bias Researcher expectations can lead to observer bias Can influence observation Can influence reality Double blind the person being observed an observation whose true purpose is hidden from both the observer and Graphical Representations Frequency Distribution number of times each measurement was made a graphic representation of measurements arranged by the The Ohio State University 2 Carlos Andres Rodriguez Herrera 1 31 23 Normal Distribution most measurements are concentrated around the middle a mathematically defined frequency distribution in which Negative Skew elongated tail at the left Positive Skew elongated tail at the right Snapshot of the data with a statement numbers usually Descriptive Statistics Central Tendency Statements about the value of the measurement that tend to lie near the center of the frequency distribution middle value when ordered from lowest to highest value of most frequently observed measurement average of all the values Mode Median Mean Variability Range value of the largest measurement in a frequency distribution minus the value of the smallest measurement Standard Deviation measurement in a frequency distribution and the mean of the distribution a statistic that describes the average difference between the Explaining Our Data You ve collected data and you have nice figures What does it mean Correlation Causation Drawing conclusions We are looking at variables hurray Patterns of Variation a pair of variables 1 Measure 2 Repeat Step 1 until you have a series of measurements of your specified variables 3 Try to discern a pattern in the series of measurements Correlation examines the extent to which two variables are related Only shows that a relationship exists between variables but cannot show causation Advantages allows us to determine if a relationship exists between two variables Disadvantages cannot determine causation often misinterpreted by the media Correlational Design Measuring Correlations Indicated by r Correlations can be positive negative or zero 0 Correlations range from 1 1 Correlations have Direction or Magnitude the absolute value of r Smaller absolute values means a weaker relationship Correlation Direction Negative as one variable increases the other variable decreases Example as drinks week increases score decreases The Ohio State University 3 Carlos Andres Rodriguez Herrera 1 31 23 Positive as one variable increases the other variable increases Example as time spent studying increases score increases Correlation Magnitude Indicates the strength of the relationship Weak r 0 1 0 2 0 3 Strong r 0 7 0 8 0 9 1 0 Zero correlation means no relationship r 0 Causation We love to make cause and effect connections Natural correlations Sometimes we jump to conclusion a little too quickly Poor diet heart attacks Storms flooding Heat sweating We know that variables are related but not why or what kind of relationship they have Third Variable Issues two variable are correlated only because each is causally Third Variable Correlation related to a third variable Third Variable Problem be inferred form the naturally occurring correlation between them because of the ever present possibility of a third variable