| Course | HS865 Doctoral Project II: Research |
|---|---|
| Unit | Unit 7 |
| Paper type | Gap statement |
| Length | About 850 words, 6 pages double-spaced |
| Format | APA 7 student paper |
| School | Purdue University Global |
| Program | Doctor of Health Science (DHSc) |
| Updated | October 2026 |
Free sample paper for HS865 Unit 7
One Sentence, Three Pages of Proof: A Unit 7 Gap Statement for a Study of Why Radiographers Keep Gonadal Shielding
[Student Name]
Purdue University Global
HS865: Doctoral Project II: Research
Unit 7 Gap Statement
[Instructor Name]
[Date]
The study is composite; the studies and frameworks cited are real.
The Gap
Although the case against routine gonadal shielding is settled and surveys show the practice persisting among radiographers who know the guidance, no study has systematically examined which behavioral determinants sustain routine shielding among radiographers in the United States since 2019, or how those determinants operate in practice.
What Is Known
The physical and anatomical rationale for routine shielding has weakened. Present-day risk models treat the gonads as less radiosensitive than older ones did, and a shield in the beam can raise exposure or hide what the image needs to show (Marsh & Silosky, 2019). Shields are frequently misplaced in children (Fawcett & Barter, 2009), partly because young girls' ovaries often lie outside the area a shield covers (Fawcett et al., 2012). These findings are consistent across studies and are not in dispute.
What Has Been Measured
Surveys have measured how often radiographers and educators use or teach shielding and whether they know the current guidance. Before the change, most educators in an international sample taught routine shielding (Shanley & Matthews, 2018). After it, surveys of practicing radiographers, including a large European survey, have measured continued use (Federico et al., 2026). Several surveys have listed reasons for shielding, such as patient requests and departmental habit, as single items.
What Has Not Been Examined
Three things are missing. First, no study has measured determinants with a validated framework, so the reasons reported are the ones researchers thought to ask about. Second, no study has paired questionnaire data with interview accounts of shielding decisions in the room, for example how a parent's question shapes a radiographer's choice in the moment. Third, almost all practice surveys come from outside the United States, where professional bodies, regulations and training differ.
The literature can say that informed radiographers still shield; it cannot yet say why, in a form that would tell a department what to change.
How the Search Supports the Claim
The claim that the gap exists rests on the documented search reported in Unit 2, covering databases, hand searching and gray literature, with the practice strand restricted to work published since the 2019 statement. Of [23] included studies, none used a behavior change framework to measure determinants of shielding, none combined survey and interview data on the question, and [2] were conducted in the United States. The search strings, dates and yields are reported in the search log so the committee can verify the absence rather than accept it.
How This Gap Differs From the Limits of Past Studies
A gap belongs to the body of evidence, not to any single study. The included surveys each have limits, small samples, single countries, self-report, but those limits do not by themselves create the gap. Even if every survey had been large and well designed, the literature would still lack a framework-based account of determinants and an explanation of how they work in practice, because no study set out to provide one. Distinguishing the gap from study limitations matters because a project that merely repeats an existing survey with a larger sample would fix a limitation without filling the gap.
Why the Gap Matters
Departments trying to end routine shielding have mostly relied on education: memos, in-service sessions and updated protocols. If shielding persists among radiographers who already know the guidance, more education will not change it. Knowing which determinants matter, such as social influence from patients and colleagues or cues in the room's environment, would point to different actions, such as scripts for conversations with parents or removing shields from default positions. Frameworks that link determinants to intervention types make this connection explicit (Michie et al., 2011).
Alternatives Set Aside
Two other gaps were considered. The first was the effect of ending shielding on image quality and repeat rates in American departments, an outcome question that would need a before-and-after comparison across sites and time beyond the program. The second was patient and parent attitudes toward the removal of shields, an important question but one that would require recruiting families, adding ethical and logistical complexity. Both are named as directions for future work. Setting them aside keeps the project focused on the question the review identified most clearly, and naming them shows the committee that the choice was considered rather than accidental. Each could build on this study's findings: knowing which determinants sustain shielding would help design both an outcome study and a study of family attitudes.
How the Gap Leads to the Study
The gap points to a study that measures determinants across the full range of a validated framework (Cane et al., 2012), in an American setting, with both a survey to show which determinants differ between radiographers who shield and those who do not and interviews to explain how those determinants operate. The methodology draft will specify that design.
References
Cane, J., O'Connor, D., & Michie, S. (2012). Validation of the theoretical domains framework for use in behaviour change and implementation research. Implementation Science, 7, 37. https://doi.org/10.1186/1748-5908-7-37
Fawcett, S. L., & Barter, S. J. (2009). The use of gonad shielding in paediatric hip and pelvis radiographs. The British Journal of Radiology, 82(977), 363-370. https://doi.org/10.1259/bjr/86609718
Fawcett, S. L., Gomez, A. C., Barter, S. J., Ditchfield, M., & Set, P. (2012). More harm than good? The anatomy of misguided shielding of the ovaries. The British Journal of Radiology, 85(1016), e442-e447. https://doi.org/10.1259/bjr/25742247
Federico, L., Roletto, A., Manzo, L., Canulli, L., Nieri, I., Panci, S., Catania, D., Rainford, L., & Gerasia, R. (2026). Survey on the use of patient contact shielding during radiological practice: The European radiographers' perspective. Radiography, 32(1), 103241. https://doi.org/10.1016/j.radi.2025.103241
Marsh, R. M., & Silosky, M. (2019). Patient shielding in diagnostic imaging: Discontinuing a legacy practice. American Journal of Roentgenology, 212(4), 755-757. https://doi.org/10.2214/AJR.18.20508
Michie, S., van Stralen, M. M., & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6, 42. https://doi.org/10.1186/1748-5908-6-42
Shanley, C., & Matthews, K. (2018). A questionnaire study of radiography educator opinions about patient lead shielding during digital projection radiography. Radiography, 24(4), 328-333. https://doi.org/10.1016/j.radi.2018.04.001
What the HS865 Unit 7 assignment asks for
The seventh unit usually asks candidates to write a gap statement of two to four pages, centered on a single sentence that names what is not known. The surrounding text should show what is known and what has been measured, so the absence is visible rather than asserted. Instructors expect the claim to rest on the documented search. Many prompts ask candidates to distinguish a gap in the body of evidence from limitations of individual studies and to explain why filling the gap matters to practice or theory. Naming alternative gaps that were considered and set aside shows a deliberate choice. The statement should end by pointing to the design that will address the gap, which the methodology unit will specify.
Inside the HS865 Unit 7 example
The gap sentence opens the document. A section on what is known summarizes the settled dose and anatomy evidence. A section on what has been measured describes educator and practice surveys and reasons listed as single items. Three things not examined follow: framework-based measurement, combined survey and interview data, and American settings. The highlighted sentence states what the gap prevents a department from doing. The search section reports what the included studies did and did not do. Further sections separate the gap from study limitations, explain why it matters for de-implementation efforts, set aside two alternatives and point toward the design.
Reading the HS865 Unit 7 grading rubric
Gap statements are commonly assessed on precision of the gap sentence, evidence that the gap is real, significance, distinction from study limitations and logical connection to the proposed design. The evidence behind the claim usually decides the grade, so reviewers expect to see the search and what existing studies did and did not do. Precision rewards a single sentence that names population, setting, period and what is unknown. Significance earns credit when the statement explains what practice could do differently once the gap is filled. Distinguishing a gap from limitations signals methodological maturity. Naming alternatives set aside and leading clearly to the design complete the score, along with accurate citations. A gap sentence that a reader could test against the search log, line by line, tends to impress committees most.
Common HS865 Unit 7 mistakes, and how to avoid them
The most frequent weakness is asserting that "little research exists" without showing the search or what existing studies did. Another is confusing a gap with a limitation, proposing to repeat a known study with a larger sample. Some candidates name gaps so broad that no single project could fill them. Others describe several gaps without choosing one. A gap that matters only to researchers, with no consequence for practice, can weaken a professional doctorate. If your project addresses another question, perhaps why a screening protocol is skipped or why a tool goes unused, send your review summary, and a gap statement can be written around one precise sentence.
Get an HS865 Unit 7 example written to your instructions
Gap statements sit in different places depending on the template: a standalone assignment, a paragraph inside a chapter, or a short memo to the chair. Attach the Unit 7 prompt, the rubric and your review or matrix. You receive a gap stated in one checkable sentence, with the evidence and the rejected alternatives set out around it. First custom sample free, 24-48h. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
More HS865 papers and DHSc samples
- HS865 Unit 1: Summary Versus Synthesis Post
- HS865 Unit 2: Literature Search Strategy Log
- HS865 Unit 3: Shielding Literature Synthesis Matrix
- HS865 Unit 4: Gonadal Shielding Thematic Review
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- HS865 Unit 6: Survey Rates Seminar Reflection
- HS865 Unit 8: Methodology Draft
- HS865 Unit 9: Instrument Alignment Table
- HS865 Unit 10: Review Chapter Draft
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HS865 Unit 7 questions, answered
What makes a research gap convincing?
Evidence that the absence is real and that filling it would matter. That means showing what existing studies did and did not do, citing the search behind the claim, and wording the gap narrowly enough that a reader could check it. A gap resting on the phrase little is known, with nothing behind it, is the version reviewers treat most skeptically.
Is a gap the same as a limitation of past studies?
Not quite. Limitations belong to individual studies, such as small samples or single sites. A gap belongs to the body of evidence: something no study, or no adequate study, has addressed. Repeated limitations can create a gap, for instance when every study measures reasons with a single item, but the statement should draw that connection explicitly.
Should I mention gaps I decided not to pursue?
Often, yes. Naming one or two alternatives and explaining why they were set aside shows the committee a considered choice, and it answers the question of why this gap and not another before anyone asks. Keep the explanation brief and tied to feasibility, sequence or scope rather than to preference or interest.
Where can I find a free HS865 Unit 7 sample paper?
The complete Unit 7 gap statement is on this page, defining one sentence about the determinants of gonadal shielding and showing the evidence behind it.
How is a gap different from a limitation?
Limitations belong to single studies, such as small samples. A gap belongs to the whole body of evidence: something no study set out to answer.