Research process
research question and hypothesis
define variables and measurements
study design
sampling
data collection
analyze data
develop conclusions and report findings
think critically and refine hypothesis
Psychology is a(n) ________________ discipline.
evidence-based
Construct
intangible, abstract attributes that are theorized to underlie observable behavior
indirectly observable or measurable
hypothetical psychological mechanism that we can’t easily observed
Happiness
subjective
abstract attribute
example of a construct
How do we measure happiness?
measure smiling behavior, which is an observable behavior that we theorize indication of the presence of happiness
it isn’t happiness itself
but we can use it to indirectly measure happiness
many ways to operationalized
Operationalizing the construct
indirectly measure construct through observation, measurement of behavior or experiences that we theorize that they are associated with it
when we define and measure a construct, indirectly through an observable behavior, then that measurement procedure becomes our operational definition of the construct
operational definition doesn’t actually refer to the construct itself, it is how we observe and define the construct through indirect measurement
Intelligence
construct
physically intangible
performance on IQ test (intelligence quotient) is an operational definition of intelligence
Research question
the broad question, idea, or problem that you wish to investigate during a research project
psychologist choose research question in their area of interest
What are the 3 types of research question?
association/relationship
difference
prediction
What do research questions come from?
inspired by personal interest
observation (own or others)
practical problems
theories
important to do a literature search and review to inform your research question
to read about relevant articles on the same area to know what have been done before and most recent
refine board question into a testable statement that can be examined during the research process
Qualities of a good hypothesis
logical: should logically follow your literature review and have a logically argument supporting your hypothesis
testable: contains observable and measurable phenomenon
narrow and specific compared to the research question
falsifiable: research study data can either support hypothesis or not support it
predictable: predict something will happen
Variable
a characteristic or condition that can change on different value for different people
anything that can vary amongst the population
can be intangible (ex. IQ) or concrete (ex. height, weight)
operationalized by using a measure in psychological research
Independent variable (IV)
causal or influential
Dependent variable (DV)
effected or influenced by IV
Continuous variable
allows for decimal or fractional values to be obtained between points on a scale when measured
ex. distance, weight, time
Discrete variable
includes separate indivisible
only allow whole values
values that can’t meaningfully exist between points on a measurable scale
ex. number of people in your family
4 scales of measurement
nominal
ordinal
interval
ratio
determined by measure used
Nominal scale
involves scale based on category
no ordering
different values don’t indicate differences in magnitude
indicate membership to different categories
ex. gender, marital status, college major, and blood type
Ordinal scale
indicate order
doesn’t tell magnitude
ex. first place, second place, third place in a running race
Interval scale
indicate actual amount of something with equal unit of measurement separating 2 scores on a scale, but there is no real zero (zero doesn’t mean a complete absence of something)
zero is arbitrary
ex. temperature
Ratio scale
indicate an actual amount of something with equal units of measurement separating each scores on a scale, but it has a real zero point
ex. distance of 2 objects
Research design
format and structure of a research project in terms of the things participants were asked to do, the way they are grouped or not, the way data and variables are collected, how the project progresses over time
deal with research question and inform type of data analysis we end up doing
5 main types of research design
descriptive
correlational
experimental
quasi experimental
non-experimental
Descriptive research design
concern with measurement and description of the natural state of individual variables as they are experienced via certain group of people
no experimentation and nothing is manipulated
focus on observation
Correlational research design
investigate relationship between variables
no experimental manipulation
variables are observed as they naturally exist
each participants provide 2 pieces of data, one for each variable
relationship between variables would mean changes in values on one variable are systematically and predictably accompanied by changes in another variable
gather evidence for association
cannot make evidence for cause-and-effect
can have a third variable that explains causal relationship, at least to some degree
Experimental research design
determining cause-and-effect in a relationship between variables
have 2 core features: involve manipulation of the hypothesized IV in a relationship
involve of carefully controlled experimental conditions in order to increase internal validity
control→ random assignment of participants to different groups
Internal validity
degree of confidence we have in a direct relationship between IV and DV in a psychological research study
by carefully controlling experimental conditions, the likelihood of encountering confounding variables for the study findings are reduced, and internal validity is strengthened
Quasi-experimental research design
investigate cause-and-effect relationship and some attempt is done to control extraneous variables
less controlled than experimental research design in that they don’t include random assignment to experimental participant’s group
ex. female vs male
Non-experimental research design
similar to correlational design
concern of demonstrating a relationship between variables but didn’t attempt to explain cause-and-effect
involve observation of two or more groups of people and one variable
variables are observed in a natural environment without manipulation and groups can be compared
What is the goal of conducting psychological research?
when we conduct psychological research, our goal is to understand some phenomenon that is experienced by a population of interest
Population
everyone of relevance to a research study
impossible to investigate everyone in the population, only a small portion of the population will be part of the study
Sample
a group of people from the population that participate in the study
What does psychological research try to achieve?
try to make a reasonable inference about things we are really interested in
select samples that are as representative as possible
Probability sampling
describes a number of sampling techniques that can be applied when the precise details of the population is known and the probability of any particular individual being selected for a research study can be determined
ex. random sampling
Random sampling
a random selection process ensure that each individual in the population has an equal probability of being selected for a research study
Strength of random sampling
free of any form of selection bias that can confound the study results
Limitation of random sampling
cannot guarantee the sample is representative of the population
often not possible in psychological research given that population’s precise characteristics are commonly unknown
Non-probability sampling
can be vulnerable to selection bias, which can affect the degree to which the sample is representative to the population
ex. convenient sampling
Convenient sampling
comprises sample that are easy or convenient to recruit
without careful control, the convenience sampling can be bias in some ways that impair researcher’s ability to generalize findings to the population
Common method to control sampling bias in convenient sampling
use quotas
involves the identification of subgroups in the accessible population, and setting recruitment quotas to ensure that they are equally representative in the population
sometimes can be even more bias, because the quotas can be set to target a predetermined set of population’s subgroup portion
can set corresponding sampling quotas
quotas may not control all the sampling bias that can occur in the convenience sampling
importantly, researchers make the best sampling decision if possible and are transparent about those decision in their reporting. this allows findings and claims about the population can be critically evaluated
Good ethical practices
ensure the welfare and dignity of those participating in a research and to ensure that the reporting of psychological is accurate and honest
Ethics in Australia is governed by?
National health and medical research council (NAMRC)
they published recommendation in the national statement on ethical conduct in human research
Guiding principle of research
merit and integrity
justice
beneficence
respect
Merit
justify by its potential benefit to humanity, either in terms of benefits to knowledge and understanding or more tangible outcomes such as improve social welfare or wellbeing for individual
more scientific so it is easier to achieve its aim
psychological research often perform initial review of relevant literature, which predicts the likely merit of the given study and additionally be valuable in informing the approach to designing that study
Integrity
research that perform according to well-founded principle of research conduct, where the researcher have conducted and reported the research honestly and transparently, whether or not the proposed hypothesis is supported
Justice
ensure that the inclusion and exclusion of participants is fair and equitable
no unfair burden placed upon any particular participant groups, that participants are not exploited in any way, that the benefit of participation is distributed fairly, and there is fair and equitable access to the benefits of the research
Beneficence
consider risks and benefits
research should involve likely benefits to either participants or the community that would justify any risks or discomfort to participants
potential risks that is associated with participation in research are minimized and controlled
researchers are responsible for clearly explaining to participant the risks and benefits of the research
this information should be given to potential participants prior to their involvement of the study
can be simple, but it is very important
once participants acknowledge the risks and benefits, they can decide whether to consent to join the study
Respect
builds on application on other core principle in research
holding regard for the value of participants and of their culture, belief, and welfare
respect privacy and confidentiality of people participating in the research project and must empower people to make decisions about their participations and the data they contribute to research studies
How do you ensure that a research project is planned appropriately, in terms of various ethical considerations?
researchers submit a research proposal to an ethics advisor, group, or committee
provide helpful advice
ask for additional requirements to be met
alternatively approve or disprove the project
a human research committee must approve a research proposal before psychological research can commence
What does the research proposal provide?
an account to the background to the project in terms of the literature or other important contexts
a detailed account of the research methodology
a description of how potential risk will be managed
a copy of all the measures that will be used
clear explanation of what participants would be asked to do and how they would be supported
copies of all documentations that participants will be given, which usually include plain language statement, a consent form, and a debriefing statement are also reviewed
Is psychological research more qualitative or quantitative?
quantitative
focus on methods that allow us to measure psychological phenomenon as precisely and unambiguously as possible
use numerical scales of measurement
ex. Likert scale
Frequency distribution
when we organize a distribution of scores by grouping the number of individuals located at each point on the scale of measurement
easily interpreted and is most commonly presented in a form of a graph or a table
Histogram
use to graph frequency distribution
easier to understand and see the distribution
Normal distribution
bell-curve
Positive skew
is a distribution is tilted to the side
the bulk is tilted to the left
major of the score is low
long right hand tail
Negative skew
opposite of positive skew
bulk falls to the right
long left hand tail
Relative frequency
express number of observation in each category as a proportion of the total number of the observation in the variable in the form of percentage
Cumulative frequency
proportion of observation for each score category accumulates to yield 100% of the observations for the variable
Box plot
low score (25%) is presented at the bottom of the graph, high score (25%) is presented at the top, middle portion (50%) is in the middle
the lines with caps at the end are called whiskers
outliers can be out of the whiskers and be presented as a blue dot
Central tendency
a summary measure that attempts to describe a whole set of data with a single value that represents the middle or center of its distribution
what is most representative or typical for a distribution
include mean, median, mode
Mean
average
add up all the score and divide that by the number of score that there were
use with interval and ratio data
normal distribution
Median
middle score
first rank the data from lowest to highest
50th percentile in a distribution
hold up against outlier
use when data is skewed or has outliers
with ordinal scales of measurement
Mode
most common score
use with discrete data
with nominal scales of measurement
Variability
how scores are spread throughout a distribution of data
tell us how representative the mean is of its distribution
if the data is packed around the mean, variability is low, which means the mean is a good representative of the scores
What does psychological research focus on?
precision
3 quantitative measure of variability
range
interquartile range
standard deviation
Range
distance covered by the entire distribution, from smallest to largest
largest minus smallest
Interquartile range
measures distance in a distribution from scores falling in the first quartile, or 25% percentile, to the scores falling in the third quartile
use it when it is appropriate to use a median
Standard deviation
average amount that scores differ from or deviate from the mean
square root of variance
Deviation score
how far each score deviated from the mean
mean minus the raw score
minus means that the raw score is below the mean
deviation score is squared to make it positive to prevent it from cancelling each other
Sum of squares
sum of squared deviation scores in a distribution
Variance
sum of squares divided by one less than sample size
squared standard deviation
Degree of freedom
n-1
Critical thinking
active process of information consumption and scrutiny
involve thinking if there are evidence to support the claim, if the evidence was of good quality, is it likely to be bias, did the claim logically followed the evidence provided, etc.
Scientific argument
consists of a number of statements (premises) that are intended to provide support for a solution
ex. deductive argument, inductive argument
Deductive argument
start with a broad premise(s)
premise(s) are used as a support to have a specific conclusion
derive suitable hypothesis to test a theory
consider valid if the conclusion necessarily follows the premise(s)
Inductive argument
include premises that include specific observation, which are intended to provide support for a conclusion in the form of a broader inference, a generalized explanation, or theory
commonly used to interpret and explain the results that are forthcoming from psychological project
doesn’t provide absolute support for its conclusion
provide probabilistic support for the conclusion
based on the premise, the conclusion is more or less likely to be true
strong inductive argument=good support (likely)
What does theories contain?
hypothetical mechanisms and intangible elements
although cannot be seen, but we assume it exists and assume it is real, because they can explain behaviors we see
a set of statements about the mechanisms underlying a particular behavior
help organize and unify different observations of behavior and relationship with other variables
generates prediction about the behavior
Validity
the degree to which the measurement process measures the variable that it claims to measure
especially important whenever an operational definition is used to measure a hypothetical construct
Face validity
unscientific form of validity
simplest and least scientific definition of validity
concerns the superficial appearance of a measurement procedure
based on subjective judgement and is difficult to quantify
high level of face validity can create problem
ex. if the purpose of measurement is obvious, the participants can see exactly what is being measured and may adjust their answers to produce a better image of themselves
Concurrent validity
demonstrate the scores obtained from the new measurement technique are directly related to the scores obtained from another, better-established procedure for measuring the same variable
establish consistency between 2 different procedures for measuring the same variable, suggesting that the 2 measurement procedures are measuring the same thing
because one procedure is well established and accepted as being valid, we infer that the second procedure must also be valid
Predictive validity
when the measurements of a construct accurately predict behavior
Construct validity
demonstrate that measurements of a variable behave in exactly the same way as the variable itself
need to examine many past researches
Convergent validity
create 2 different methods for measuring the same construct, and then showing that the 2 methods produce strongly related scores
demonstrate that different measurement procedures converge
Divergent validity
demonstrate that we are measuring one specific construct and not combining 2 different constructs in the same measurement process
differentiate between 2 conceptually distinct construct by measuring both constructs and then showing that there is little or no relationship between the 2 measurements
Reliability
produces identical results when it is used repeatedly to measure the same individual under the same conditions
stability or consistency of the measurement
Most common sources of error that leads to inconsistency
observer error
environmental changes
participant changes
Test-retest reliability
successive measurements
compare the scores obtained from 2 successive measurements
use exactly same measurement procedure for the same group of individuals at 2 different times
Parallel-forms reliability
successive measurements
different versions of the instruments are used for the test and the retest
determined by computing a correlation to measure the consistency of the relationship between the 2 sets of scores
Inter-rater reliability
simultaneous measurement
degree of agreement between 2 observers who simultaneously record measurements of the behaviors
measured by computing the correlation between the scores from the 2 observers
Split-half reliability
internal consistency
splitting the items on a questionnaire or test in half, computing a separate score for each half, and then calculating the degree of consistency between the 2 scores for a group of participants
Demand characteristics
any potential cues or features of a study that suggest to the participants what the purpose and hypothesis is and influence the participants to respond or behave in a certain way
Reactivity
participants modify their natural behavior in response to the fact that they are participating in a research study or the knowledge that they are being measured
Method of tenacity
holding on to ideas and beliefs simply because they have been accepted as facts for a long time or because of superstition
Method of intuition
information is accepted as true because it feels right
Method of authority
relies on information or answer from an expert in the subject area
Method of faith
variant of method of authority, in which people have unquestioning trust in the authority figure and accept information from the authority without doubt or challenge
ex. kids trust adults