Quan Research – Flashcards

Begins with a _____ and very specific hypotheses that address one defined issue

research is done from _____ point of view

Quantitative seeks to indentify ____ relationship

Sampling methods include

attempts to specify a random sample from segments of a larger population that will be representative of the whole.

any differences between the groups are small and only due to chance; everyone in the study has equal chance of treatment or control group.

no way to guarantee that each element of a population will be included in the sample.

Everyone in the population has an equal chance of being selected

A population with different strata, or subgroups (i.e., gender, education level, religion) Random selection of equal number of samples from each strata Example: High School Students' Interest in Majoring in a STEM Field: Insight into High School Students' Postsecondary Plans

A population with different strata, or subgroups, of different sizes Cyberbullying in college Population is 10,000 students (8,000 are residential and 2,000 are commuters); want a proportional sample of 1,000 (800 residential and 200 commuters)

Use when the studied population is spread across a wide area and it may not be feasible to study everyone Is important that clusters be as similar to one another as possible with each cluster containing an equally heterogeneous mix of individuals Identify clusters or intact naturally occurring groups (zip codes, school zones, precincts, airports, geographical regions etc.) . ex: Healthcare and the Homeless on Long Island

Selecting individuals, or clusters, according to a predetermined sequence, which originates by chance Example: Opinions of Suffolk County residents about the Affordable Care Act (Select a random number, say it's 10, then every 10th person from a master list or a group is selected)

no way to guarantee that each element of a population will be included in the sample.

readily available participants Ease in selection, like a class. SBU student data might not be generalizable to students from a small southern college

selections based on the same proportions found in the general population Let's say the number of females ages 36-40 are the same as those in the 41-43 age range 10 females from each age range Not random but sample is stratified well

select participants for a particular purpose Knowledge of group is required before selection Risk of researcher selection bias

identify potential subjects in studies where subjects are hard to locate.

degree to which extraneous variables have been controlled; experimental effects can be attributed solely to treatment/intervention

An experimental design with four groups-some receive the intervention, others serve as controls; some are measured before and after, other are measured only after the intervention. Pre-test Treatment Post-Test E R1 O X O C R2 O O E R3 X O C R4 O

(first 2 groups of the Solomon four): controls for many threats to internal validity E R1 O X O C R2 O O

Posttest-only control group: sometimes you can not pretest (last 2 groups of the Solomon four): controls for threats to internal validity R1 X O R2 O

one group receives 2 treatments (simultaneously or very close together) useful when effects of each treatment are temporary and localized G1 X1 O X2 O ____________________________________ R1 X1 O X2 O

A fitness instructor wants to test the effectiveness of a performance-enhancing herbal supplement on students in her exercise class. To create experimental groups that are similar at the beginning of the study, the students are assigned into two groups at random. Students in both groups are given a pill to take every day, but they do not know whether the pill is a placebo or the herbal supplement. The instructor gives Group A the herbal supplement and Group B receives the placebo. The students' fitness levels is compared before and after six weeks of consuming the supplement of the sugar pill. No differences in performance ability were found between the two groups, suggesting that the herbal supplement was not effective. How would you notate this study, using the designs we just discussed? R1 O x O R2 O O

Can be very similar to experimental designs with the exception of random assignment. Can include control groups but can not yield cause-effect results Random assignment is not always possible

-Nonequivalent (randomized) -Control Group Pretest-Posttest -Simple Time Series -Control Group Time Series -Multiple Baseline Design

several measurements of the dependent variable over time. G1 O1 O2 O3 X O1 O2 O3

The measurements prior to intervention are called

yields greater internal validity; parallel series of observations G1 O1 O2 O3 X O1 O2 O3 G2 O1 O2 O3 O1 O2 O3

Nonequivalent (non-randomized) Control Group Pretest-Posttest design G1 O X O G2 O O

Shows the effect of a treatment by initiating it at different times for different groups or individuals, or perhaps in different settings for a single individual Group Time G1 O x O x O G2 O O x O

-non randomization, no equivalent control group, no cause-effect relationship -One-shot experimental case study -Very poor internal validity -Results can be influenced by a multitude of factors **This is one of the weakest deigns and should be avoided**