DQ 1 : Provide examples of experimental and nonexperimental research designs
Two examples and one contrast, and the contrast is the graded part. Control is not a single dial: manipulation, randomisation and comparison groups vary independently, which is exactly why quasi-experimental designs exist.
Editorial process
Last reviewed · August 18, 2026
Examples are cheap — the levels of control are the assignment
Give the examples quickly and spend the post on control, because control is what the second sentence asks for and it is the harder idea. Experimental designs have three features working together: the researcher manipulates the independent variable, participants are randomly assigned, and there is a comparison group. Nonexperimental designs — descriptive, correlational, cohort, case-control — observe what is already happening. The useful move is to treat those three features as separate dials rather than one, because that is what makes quasi-experimental designs intelligible instead of a vague middle. A unit that introduces a sepsis screening tool and compares outcomes before and after has manipulation and a comparison, and no randomisation at all. Naming which dial is missing tells your reader exactly which threat to validity has been let in, and that is a far stronger answer than saying one design has more control than the other.
Choose nursing examples where you can say what the missing control costs. A randomised trial of two wound dressings controls for the unknown differences between patients; a correlational study of nurse staffing ratios and patient mortality cannot, so its finding remains an association that plausible confounders such as case mix or hospital resources could explain. That is not a reason to dismiss nonexperimental work, and saying so protects you from the commonest mistake in this discussion, which is treating observational designs as inferior rather than differently purposed. Many nursing questions cannot be randomised for ethical or practical reasons, and no one is going to randomise patients to understaffed units. Close by matching design to question: manipulation where it is possible and ethical, observation where it is not, and be explicit about what each choice buys you and what it forecloses. The strongest close names a question you could not randomise, and the design you would use instead.
Likely learning objectives
- Identify the three features that jointly define an experimental design.
- Place a quasi-experimental study correctly by naming the feature it lacks.
- Contrast two designs on validity threats rather than on a single quality ranking.
- Justify a nonexperimental design where randomisation is not ethically available.
Assignment instructions
Read the full question
Review every instruction before using the planning guidance that follows.
NURS 433 Topic 3 DQ 1 DQ 1 : Provide examples of experimental and nonexperimental research designs Provide examples of experimental and nonexperimental research designs. Contrast the levels of control applied to each.
Turn the brief into deliverables
- 01One example of an experimental design in a nursing context.
- 02One example of a nonexperimental design in a nursing context.
- 03A contrast of control that separates manipulation, randomisation and comparison.
- 04A statement of what the weaker control costs in interpretation.
- 05A defence of nonexperimental work where randomisation is unavailable.
Two examples, then a control comparison that actually contrasts
An experimental example from nursing
Describe a randomised nursing study and identify its manipulation, assignment and comparison.
What the assessor is likely looking for
All three experimental features located in one real study.
A nonexperimental example from nursing
Describe a descriptive or correlational nursing study and what it can claim.
What the assessor is likely looking for
A claim limited to association rather than stated as an effect.
Control, taken apart into three dials
Contrast the designs feature by feature rather than on an overall ranking.
What the assessor is likely looking for
The quasi-experimental middle placed correctly by the feature it lacks.
What the missing control costs
Name the specific validity threat each design leaves open.
What the assessor is likely looking for
A named confounder or bias, not 'less reliable results'.
Matching design to the nursing question
Close on when observation is the right choice rather than the fallback.
What the assessor is likely looking for
An ethical or practical reason randomisation is unavailable for a stated question.
Where to find nursing studies of each design
Recommended databases
- NCBI Bookshelf
- PubMed Central
- CINAHL Complete
- Office of Research Integrity
Search sequence
- 1.Fix the design vocabulary from an epidemiological study-design overview first.
- 2.Find one randomised nursing intervention trial in PMC and note how it reports allocation.
- 3.Find one correlational nursing workforce study and note how carefully it words its conclusion.
- 4.Read a descriptive-designs primer so your nonexperimental example is classified precisely.
Reference shortlist
These are authoritative starting points, not a ready-made bibliography. A qualified reviewer must confirm that each source fits the assignment and supports the claim beside which it is cited.
Epidemiology Of Study Design
StatPearls, NCBI Bookshelf · 2023
The study-design hierarchy, for placing your two examples and the quasi-experimental middle.
Research Design: Descriptive Studies
Office of Research Integrity, U.S. Department of Health and Human Services · 2024
A concise account of descriptive designs and what they can and cannot claim.
Human Subjects Research Design
StatPearls, NCBI Bookshelf · 2023
Human subjects research design, including where randomisation is ethically unavailable.
Study Bias
StatPearls, NCBI Bookshelf · 2023
Study bias — the named threats that follow from each missing control feature.
Types of Variables and Commonly Used Statistical Designs
StatPearls, NCBI Bookshelf · 2023
Variables and the designs that use them, for tying manipulation back to the independent variable.
Review before submission
Common mistakes
- Treating control as a single scale and ranking designs on it.
- Calling every non-randomised study 'nonexperimental' and missing quasi-experimental entirely.
- Describing nonexperimental designs as inferior rather than differently purposed.
- Giving two examples and never returning to the contrast the prompt asked for.
Submission checklist
- Have you named all three defining features of an experimental design?
- Does your contrast say which specific feature each design lacks?
- Have you named a validity threat that follows from the missing feature?
- Is there a nursing question in your post that could not ethically be randomised?
- Do both examples come from health care rather than from a textbook illustration?
Use this guide to plan and review your own work. Follow your institution's rules and read Brinevia's academic-integrity policy.
Written by
Maren Caldwell
MSN, RN, CNE
Medical-surgical nursing, pharmacology and NCLEX preparation
Maren is a registered nurse with over 15 years of clinical and educational experience in medical-surgical nursing. She writes on NCLEX preparation, patient care fundamentals, pharmacology and evidence-based practice.
Reviewed by
Dr. Tessa Redmond
DNP, RN, CNE
Evidence-based practice and clinical education
Tessa is a doctorally-prepared nurse educator. She reviews Brinevia content for clinical accuracy and alignment with current evidence-based guidelines.