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What are the steps in the Scientific Method, and what happens at each step
step 1: identify problem; step 2: research the area, primary and secondary sources; step 3: identify hypothesis/research question, form question based on what learned in step 2; step 4 research design; step 5 collect data; step 6 analyze data; step 7 findings and conclusions
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What are the three types of quantitative research? How do I know which one to use
Descriptive (current conditions), correlation (relationship), Experimental (differences, effects)
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What are the two main levels of data
continuous, categorical
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What do the terms target population mean
entire group of people of interest from which sample will be selected
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What do the terms sample mean
a subgroup of the target population that will hopefully participate in our research
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What is meant by a representative sample
sample should be similar to the population on the characteristics of interest (think back to research question
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What does the term generalization mean
The results can generalized to the population your studying
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What is the difference between random (or probability) sampling and non-probability sampling
random sampling is when all participants have an equal chance to be selected
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What are the five sampling techniques discussed class
simple random sampling, stratified random sampling, cluster sampling, systematic sampling, convenience sampling
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simple random sampling is
uses random selection, every person has equal chance, selection of one person doesn’t interfere with selection of another (put names back in hat after pick)
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Stratified random sampling is
divide the population into specific subgroups, or strata, based on a critical characteristic. A set number of research participants are randomly selected from each strata. (can do this proportionally or equally)
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Cluster sampling is
sampling unit is a naturally occurring group or clusters of members of the population, instead of sampling individual members you randomly select the clusters
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systematic sampling is
sample is drawn by choosing every kth person from a listing of the population (make sure the list is made up randomly)
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convenience sampling is
include any participants who are readily available and accessible (not random)
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When it comes to questionnaires, what is meant by validity and reliability
Validity: when questionnaire is measuring what is intended to be measured; Reliability: questionnaire measures consistently each time it is used
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What are the three ways to establish validity (as discussed in class)?
- content-related: experts in field review questionnaire
- construct related: use stats approach to be sure I am measuring the construct of (whatever) the whole construct and nothing but the construct
- criterion-related: uses two questionnaires. take questionnaire and use stats approach to determine if it correlates with certain criterion (something that theoretically, resilience should be able to predict – like optimism) the take questionnaire and determine using a stats approach if it can distinguish between resilience and something very different (like defeatism)
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What are the two ways to establish reliability (as discussed in class)?
- - alpha reliability: using stats approach to examine each item on the questionnaire compared with the other items on the questionnaire (most common one)
- - test-retest reliability: use statistical approach to examine day-to-day stability of the questionnaire by correlating day 1 scores with day 2 scores (time lapse on this one students take one day and then another day and scores should correlate)
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What do the terms statistics mean
values, quantities calculated using info obtained from a sample
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What do the terms univariate statistics mean
involves individual variables (meaning one) descriptive statistics are this kind of stats (used to describe and summarize the characteristics of the data from our sample
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What do the terms cross-sectional mean
data collected at one point in time
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With what type of quantitative research can I use descriptive statistics
all three types descriptive, correlation, experimental
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What is a frequency distribution
can be used with either type of data (continuous, categorical) its an ordered listing of the scores and their frequencies
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What are measures of central tendency and measures of variability
indicates those points at which scores tend to be concentrated
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Measures of central tendency
mean (average), median (middle score), mode (score most frequently received)
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measures of variability
- Range (difference between highest and lowest score),
- Standard deviation (indicates amount of variability among the scores in relation to the mean and how much each score deviates from the mean);
- quartile deviation (indicates the amount of deviation surrounding the median)
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What is meant by a distribution of scores
? if you collected continuous level data from everyone in your target population and created a graph, it would approach a bell curve
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What is a normal distribution
Bell curve
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What is meant by kurtosis
degree of peakedness
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What are the two types of kurtosis
leptokurtic (majority of scores in the middle); platykurtic (scores spread out smaller cluster in the middle
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What is meant by skewness
many scores on one end of the scale and progressively fewer on the other end
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What are the two types of skewness
negative (few low scores), positive (few high scores)
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What type of descriptive statistics can I use if I have categorical data
frequency distribution, visually display
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What type of descriptive statistics can I use if I have continuous data
frequency, measures of central tendency and variability
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Why do we use inferential statistics
used to make inferences from a sample to a population
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With what type of quantitative research can I use inferential statistics
correlation and experimental
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What is a hypothesis? What is it based on
a tentative explanation, a prediction or the outcome, an educated guess. Based on research question
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With what type of quantitative research would I have a hypothesis
correlation and experimental
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What are the five steps in hypothesis testing
- 1) state null and alternative hypotheses
- 2) determine significance level – Alpha (.05) 3) choose appropriate test statistic and apply it to the data from your sample
- 4) calculate p-value (computer does)
- 5) compare p-value to alpha level (reject or accept null hypotheses
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What is meant by statistical significance
means the results you got are probably true (not due to chance); that the results are good enough to be believed
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What does alpha represent
I’m willing to accept 5% probability that my results happened by chance. which means I want to be 95% confident that my results are statistically significant
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What does the p-value represent
The probability – based on the data I am actually analyzing – that my results have occurred by chance
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When would I reject the null hypothesis
p-value<.05 reject null: there is a significant relationship of significant difference
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When would I accept the null hypothesis
; p-value>.05 accept null: there is no significant relationship or no significant difference
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What is a Type I error
? type I error= reject the null when it’s actually true (I see a difference between the gourps in my sample when that difference doesn’t really exist in the population);
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What is a Type II error
accept the null when it’s actually false (I don’t see a difference between the groups in my sample, but that difference actually exists in the population
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What test statistic do I use in correlation research
Correlation – calculates r value and p value
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What level of data do my variables need to be if I want to determine if a relationship exists
continuous
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What is the null hypothesis for a correlation
? null= there is no significant relationship
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What is the alternative hypothesis for a correlation
alternative= there is a significant relationship
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What type of graph do I create to visually display the relationship between two variables
scattergram
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What does a positive relationship look like in the graph scattergram
positive: scores go in same direction. as one score increases so does the other or as one score decreases so does the other
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what does a negative relationship look like in a graph scattergram
negative: scores go in different direction as one score increases the other decreases
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What does a no relationship, look like in a graph scattergram
no relationship: no pattern
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What is the line of best fit in a graph
straight line between your data points; created by minimizing the overall distance between the points and line. shows general direction that a group of data points seems to be heading
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What does the r-value tell you
tells you the direction and strength
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What is the null hypothesis for an experiment
? Null: there is no significant difference
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What is the alternative hypothesis in experiment
alternative: there is a significant difference
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What is the difference between a nondirectional alternative hypothesis and a directional alternative hypothesis?
nondirectional= there is a difference; directional= there is a difference in a particular direction
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What are the four test statistics we could use in experimental research
Independent groups t-test, ANOVA, post hoc tests; chi square, paired samples t-test
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When would I use an independent groups t-test
compare 2 independent groups
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What level of data does my independent variable need to be in a independent groups t test
IV categorical
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What level of data does my dependent variable need to be?
DV continuous
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What are the two types of independent groups we discussed in class when it comes to independent groups t testing
groups based on existing characteristics (male female); groups based on something I control (teaching method, drug treatment)
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When would I use an ANOVA?
compare 3+ independent groups
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What level of data does my independent variable need to be? What level of data does my dependent variable need to be in ANOVA
? DV continuous; IV categorical
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What do the results of an ANOVA tell you?
tells you there is a statistically significant difference between the three mean scores
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What do the ANOVA results not tell you?
doesn’t tell you where the difference lies
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What do I need to do to determine where the difference lies between the three groups in my ANOVA?
Post – hoc test
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When would I use a Paired Samples t-test?
compare 2 dependent groups
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What level of data does my independent variable need to be? What level of data does my dependent variable need to be in a paired samples t test
? IV categorical; DV continuous
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What does it mean for groups to be dependent on each other
think pretest postest
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When would I use a chi-square?
when you have categorical data. used to determine whether significant differences exist in the number of people who are classified in the categories of the research variables
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What is the null hypothesis for a chi-square?
Null: there will be no difference between expected frequencies and observed frequencies
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What is the alternative hypothesis in a chi square
Alternative: there will be a difference between expected frequencies and observed frequencies
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What level of data do both of my variables need to be in chi square?
categorical
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What is the definition of ethics?
morals, norms for conduct that distinguish between acceptable and unacceptable behavior
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Why do researchers need to be ethical?
promotes aim of research, promote values essential to collaboration, can be held accountable to the public, promote other moral and social values
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What is an Institutional Review Board?
? examines the risks to benefits of proposed reearch studies with respect to protecting human subjects and abiding by federal regulations
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How do you define anonymous and confidential
- anonymous: inability to link any research information back to the individual respondents;
- confidential: ability of researchers to link research information back to the individual respondents but no one else can access the information
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What are the key elements of Informed consent?
voluntary no coercion, fully explained expectations described, clear description of risks and benefits, statement indicating anonymous or level of confidentiality indicates who will see the individual results of the participants, participants right to ask any questions any time receive contact info of principal investigator and IRB, statement that participants can withdraw at any time with no consequences
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What three actions are considered by the federal government to be research misconduct?
falsification, fabrication, plagiarism
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Levenes test for ANOVA
- p < .05 you reject the null – assume variances were not equal,
- p > .05 you accept the null assume variances were equal
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post-hoc test for ANOVA interpret
- Use Tukey if equal variances assumed,
- use Dunnett if equal variances not assumed (use Levene’s test to find out the variance)
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interpret the p-value for the chi-square
If p < .05 reject the null and report that there is a statistically significant difference b/w expected frequencies and observed frequencies ( with this test you hope that the numbers are proportional – which doesn’t’ mean equal numbers at beginning it means proportionate, this is what is meant by expected frequencies)
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