Research Flashcards
What are the two types of experimental design research?
Experimental research with randomization (True experimental design) (RCT)
Experimental research without randomization (Quasi-experimental)
What is true experimental research?
Manipulation
Randomization
Control of other variables
What is quasi-experimental study?
There is no random assignment. Participants may be assigned based on pre-existing conditions (e.g., by age, location, or school), which increases the likelihood of biases
What are the non-experimental (observational) studies?
Cohort (has the highest level of evidence among observational studies)
Case-control (moderate evidence)
Cross-sectional (least level of evidence)
What is cohort study?
Longitudinal time (mahabang gagawin)
In a cohort study, researchers follow a group of people (a cohort) over time to see how different exposures (e.g., smoking, diet) affect outcomes (e.g., disease development). The cohort is usually divided into exposed and non-exposed groups.
What are the two types of cohort study? What is the difference between the two?
Prospective cohort: starts in the present and follows participants into the future, collecting data over time → forward in time
Retrospective: looks back at data that already exists and examines participants’ past exposures and outcomes ← backward in time
What is a case control study?
Compares subjects with disease to those without
A case-control study is a type of observational research used to investigate the causes of a specific outcome (such as a disease or condition) by comparing two groups of people: those who have the outcome (cases) and those who do not (controls).
Most of the time we use this study for rare diseases
What is cross-sectional study?
Presence/absence of disease at a single point in time
Example for this study: prevalence
Give an example for a cohort study
Incidence (rate of new cases) of childhood apraxia of speech in preschool-aged children over a one year period
Effectiveness of early language intervention
What is the baseline?
Refers to the initial set of data collected before any interventions, treatments, or experimental changes are applied. It serves as a reference point or starting condition that allows researchers to compare the “before” and “after” effects of an intervention or change in an experiment.
Give an example of a case-control study
A study on risk factors for childhood stuttering
Give an example of cross-sectional stud
Prevalence (number of cases with the disease) of voice disorders among public school teachers
What is quantitative and qualitative study?
Quantitative study answers questions through standardized measures
What is qualitative study?
Answers questions through in-depth interviews, focused group discussions, and observations
What is reliability?
Consistency, repeatability
Test-retest → over time (consistent results over time)
Internal consistency → within a measure/instrument (there is one measurement; the questions or sub questions are consistent)
Inter-rater → across different raters/observers (consistent and judgment even if there are different raters)
Intra-rater → same rater (same observer but has consistent results)
What is validity?
Accuracy
Face → what is superficially appears to measure (based on looks e.g., weight scale)
Content → covers all aspects (Example: A math test intended to measure overall math ability should include questions covering all key areas of math (e.g., algebra, geometry, arithmetic). If it only tests algebra, it lacks content validity.)
Construct → existing theory of knowledge (is it consistent with the theory behind the concept) ( Example: construct validity is like making sure your test really measures what it’s supposed to. Just like with the drawing test, you want to check that you’re asking the right questions and that the results make sense based on what we already know about drawing.)
Criterion → gold standard of measure (This measures how well one test or measurement compares to a gold standard or established benchmark for the same concept. It assesses the test’s performance against a criterion that is already known to be valid.)
What is the validity of diagnostic tools?
Sensitivity
Specificity
What is sensitivity?
Indicated how well the tool identifies a disease
What is specificity?
Indicates how well the tool identifies absence of a disease
What is a positive test result (+)?
With disease (true positive → sensitive)
Example:
Scenario: Imagine a group of 100 people, and 10 of them actually have COVID-19 while the rest do not.
High Sensitivity: If the PCR test has a sensitivity of 90%, this means that it correctly identifies 9 out of the 10 people who have the virus.
Positive Test Result (Sensitivity): So, if one of those 10 infected individuals takes the test, there is a high likelihood (90%) that the test will come back positive for them, indicating that they have COVID-19.
What is a negative test result (-) or true negative (specificity)?
Example:
Scenario: Imagine a group of 100 people, and 10 of them actually have COVID-19 while the rest do not.
High Sensitivity: If the PCR test has a sensitivity of 90%, this means that it correctly identifies 9 out of the 10 people who have the virus.
Positive Test Result (Sensitivity): So, if one of those 10 infected individuals takes the test, there is a high likelihood (90%) that the test will come back positive for them, indicating that they have COVID-19.
Negative Test Result/True negative (Specificity): The remaining 90 people (who do not have COVID-10) all test negative
What is probability sampling?
Randomization
Simple → each member has an equal chance of being selected (Example: If there are 100 students in a school, each student has a 1 in 100 chance of being selected for a survey.)
Systematic → selecting every nth member from a population
Stratified → dividing the population into homogenous groups (strata) then randomly selecting samples from each group (Example: If a researcher wants to ensure they have an equal representation of different age groups in a study, they might divide the population into age brackets (0-18, 19-35, 36-50, etc.) and randomly select participants from each age group.)
Cluster → dividing the population into clusters (usually geographical) then selecting some clusters (Example: A researcher studying student performance might divide a city into districts (clusters) and randomly select a few districts to survey all the students within those districts.)
What is non-probability?
No randomization (Quasi experimental design)
Convenience → based on researcher’s easy accessibility (Example: A researcher might survey people in a nearby coffee shop because it’s convenient for them to reach those individuals, rather than seeking a more representative sample from the entire population.) what’s convenient for the researcher
Purposive → based on the researcher’s judgment (Example: A researcher studying a specific medical condition may select individuals who have that condition rather than randomly sampling the general population, believing that these individuals will provide more relevant insights.)
Quota → predetermined number (Example: If a researcher wants to include 50 men and 50 women in a study, they will continue to sample until they have 50 participants from each gender, regardless of how they choose those individuals.)
Snowball → word of mouth; referrals from existing participants (Example: A researcher studying a rare condition might initially interview one or two individuals who have it. Those participants then refer others they know with the same condition, helping the researcher expand their sample through these connections.)
What are tables?
Present data in rows and columns
Compare values
Purpose:
They allow for easy comparison of values across different categories or groups.
Tables can summarize large amounts of data in a clear and concise manner, making it easier for readers to find specific information.
Example: A table might show the test scores of students across different subjects, where each row represents a student, and each column represents a subject.
What is a bar graph?
Represent categorical data with rectangular bars of varying lengths
Purpose:
Bar graphs are useful for comparing different categories or groups.
They visually highlight differences between categories, making it easy to see which category has the highest or lowest values.
Example: A bar graph could show the number of students enrolled in different sports at a school, with each sport represented by a bar.
What are pie charts?
Represent the proportion of each category within a dataset
Purpose:
They visually show the relative sizes of parts to a whole.
Pie charts are effective for displaying percentages or proportions and making it easy to see how different categories contribute to the overall total.
Example: A pie chart might show the market share of different smartphone brands, with each slice representing the percentage of total sales for each brand.
What is a histogram?
Useful for understanding the shape and spread of data distributions
Purpose:
Histograms are useful for understanding the shape and spread of data distributions (such as normal distribution, skewed distribution, etc.).
They can reveal patterns, such as where data points cluster or if there are any outliers.
Example: A histogram might show the distribution of test scores in a class, with bins representing score ranges (e.g., 0-10, 11-20, etc.).
What is a scatter plot?
Useful for visualizing relationship between continuous variables
Purpose:
Scatter plots are useful for visualizing the relationship between two variables, such as whether they correlate positively, negatively, or not at all.
They can also help identify trends, clusters, or outliers in data.
Example: A scatter plot might show the relationship between hours studied and exam scores, with each dot representing a student’s hours studied (x-axis) and their corresponding exam score (y-axis).