CHAPTER 2 BOOK NOTES
2.0 Methods in Psychology
-Louise Hay, bestselling authors of all time, believes that everything that happens to us (accident
and disease) is a result of the thoughts we choose to think.
-Believes she cured herself of cancer by changing her thoughts.
2.1 Empiricism: How to Know Stuff
-Two kinds of doctors for ancient Greeks:
-Dogmatists (dogmatikos): who thought that the best way to understand illness was to
develop theories about the body’s functions.
-People who went to dogmatists tend to die a lot.
-Empiricists: who thought that the best way to understand illness was to observe sick
-Today’s meaning of dogmatism and empiricism:
-Dogmatism: tendency for people to cling their assumptions
-Empiricism: the belief that accurate knowledge can be acquired through observation.
2,2 The Scientific Method
-Scientific method: a set of principles about the appropriate relationship between ideas and
-Theory: hypothetical explanation of a natural phenomenon
-Ideas about how and why things work they way they do.
-Hypothesis: a falsifiable prediction made by a theory
2.3 The Art of Looking
-Eadweard Muybridge, invented a technique for taking photographs in rapid succession, and his
photos showed that when horses gallop, all four feet leave the ground.
-Empirical method: a set of rules and techniques for observation
-Method: techniques that enhance the powers of the senses
-Three things that make people difficult to study:
1. Complexity: the brain is complicated to study
2. Variability: people are as varied as their fingerprints
3. Reactivity: people act one way when they are being observed
-Psychologists have developed two kinds of methods that are designed to meet these challenges:
1.methods of observation: allows them to determine what people do
2.methods of explanation: allows them to determine why people do it
2.4 In Summary
-Empiricism is the belief that the best way to understand the world is to observe it.
-Scientific method suggests that our theories about the world give rise to falsifiable hypothesis.
2.5 Observation: Discovering What People Do
-Observe: to use one’s senses to learn about the properties of an event or an object.
-Measure: a device that can detect the condition to which and operational definition refers.
-To measure we must define the property we wish to measure and then find a way to
-Operational definition: a description of a property in concrete, measurable terms. -Electromyograph (EMG): a device that measures muscle contractions under the surface of a
-Good measures have three properties: validity, reliability, and power.
-Validity: the extent which a measurement and property are conceptually related.
-Reliability: the tendency for a measure to produce the same measurement whenever it is
used to measure the same thing.
-Power: the ability to detect the concrete conditions specified in the operational
-Demand Characteristics: aspects of an observational setting that cause people to behave as they
think they should.
-A “demand” that people say and do things that they normally might not
-Naturalistic observation: a technique for gathering information by unobtrusively observing
people in their natural environments.
-People being observed without any knowledge of it.
-Demand characteristics can be avoided when they cannot be identified as the originators of their
actions (I.e., anonymous questionnaires)
-Also, keeping the people who are being observed from knowing the true purpose of the
-Psychologists use ‘cover stories’: misleading explanations that are meant to keep people
from discerning the true purpose of an observation.
-Observer bias, expectations can influence observations.
-Double-blind observation: an observation whose true purpose is hidden from both the observer
and the person being observed.
-Two techniques for making sense of big pages full of numbers: graphic representations and
-Frequency distribution: a graphic representation of measurements arranged by the number of
times each measurement was made.
-Graphic representations, human beings typically find it easier to understand things when
they are represented visually.
-Normal distribution: a mathematically defined frequency distribution in which
most measurements are concentrated around the middle.
-Normal distribution is symmetrical, has a peak in the middle, and trails off at both
-Descriptive statistics, a brief summary statement that captures the essential information
from a frequency distribution.
-Two important kinds of descriptive statistics: central tendency and variability
-Central tendency: statements about the value of the measurements that tend to
lie near the center of midpoint of the frequency distribution.
-mode: value of the most frequently observed measurement
-mean: average value of all the measurements
-median: value that is “in the middle”
-range: the value of the largest measurement in a frequency distribution
minus the value of the smallest measurement.
-Standard deviation: a statistic that describes the average and the mean of that
distribution. 2.8 In Summary
-Measurement involves defining a property in terms of a concrete condition, and then
constructing a measure that can detect that condition.
-A good measure is valid, reliable, and powerful
-Demand characteristics are features of a setting that suggest to people that they should behave
in a particular way.
-Psychologists try to reduce this by observing participants in their natural habitats.
-Observer bias is the tendency for observers to see what they expect to see or cause others to
behave as they expect them to behave.
-Psychologists often describe the measurements with graphic representation called a frequency
distribution, which often has a special shape known as the normal distribution.
-Also describe their measurements with descriptive statistics, most common of which are
descriptions of central tendency and descriptions of variability.
2.9 Explanation: Discovering Why People Do What They Do
-Ultimate goal of scientific research is to discover casual relationships between properties.
-When performing a study the following should be present:
-Variables: properties whose values can vary across individuals or over time. (I.E., letters
can be used in algebra not just numbers)
-Make a series of measurements rather than making just one.
- Discern a pattern of measurements.
-Correlation: two variables are said to “be correlated” when variations in the value
of one variable are synchronized with variations in the value of the other.
-Correlation coefficient: a measure of the direction and strength of a correlation.
-Symbolized by the letter ‘r’
-Has a limited range, r can range from -1 to 1
- r=1 perfect positive correlation
- r= -1 perfect negative correlation
- r =0 uncorrelated
- Immanuel Kant, philosopher who suggested people come into the world with cause-detectors
built into their brains.
-For centuries, people believed solar eclipses cause birth defects or human sacrifices
-Natural correlation: the correlations we observe in the world around us.
-Example, violence to which a child is exposed through media and the aggressiveness of
the child’s behavior.
-Third-variable correlation: two variables are correlated only because each is casually
related to a third variable.
-To determine a third va