Collecting Data

It ensures that all students have an equal chance of being selected for the study, regardless of their initial ability.

It helps ensure that any differences between the two groups are due to the treatment, not preexisting differences.

It guarantees that both groups will have identical outcomes on the post-treatment assessment.

It allows for precise predictions about individual student performance based on group assignment.

Based on their sequential order

Based on their individual characteristics

Based on a random assignment process

Based on a variable known to influence the response variable

Range

Median

Quartiles

Outliers

To ensure sequential assignment of treatments

To control for confounding variables

To match participants based on relevant factors

To study the effects of treatments on a response variable

Randomization

Replication

Blocking

Stratification

Repeated-measures design following patients over time after receiving the medication, noting ethnic background but not controlling for placebo influences.

Cross-sectional survey assessing self-reported medication outcomes among patients of different ethnic backgrounds after administration of the medication.

Randomized placebo-controlled double-blind clinical trial with ethnic groups as blocks randomly assigning patients within each block to either drug or placebo.

Quasi-experimental study using a historical control group of patients from varied ethnicities to compare against a new drug group.

It simplifies the data analysis process

It allows for sequential implementation of treatments

It ensures equal assignment to treatment groups

It controls for known confounding variables

Open-label experiment where both doctors and patients know who receives the drug versus placebo from start of trial.

Cluster randomization by hospital units without blinding, assuming equal doctor-patient interaction across all units involved in study.

Single-blind experiment where only patients are unaware if they're receiving the drug or placebo, but doctors know their treatment assignment.

Double-blind experiment where neither doctors nor patients know who receives the drug or placebo until after data collection is complete.

Mismatched sample sizes making results non-representative

Inadequate blinding of the participants and researchers leading to expectancy effects

Selection bias due to participants' predisposition to seek out fitness-related activities

Failure to include different types of exercise regimens in the analysis

Assign all students in morning classes to the new method and those in afternoon classes to the old method.

Let students choose whether they want to be taught by the new or old method based on their learning preferences.

Randomly assign students to classes and then randomly select half of the classes for the new teaching method.

Use only volunteers for the new teaching method and compare their scores with non-volunteers using the old method.