Data Analysis, Report Writing, and Portfolio Assembly

Why This Lesson Matters

You have spent weeks designing your project, collecting field data, and maintaining your logbook. This final phase turns raw numbers into professional knowledge that employers, agencies, and dive contractors can actually use. A strong technical report and a complete portfolio are also the evidence that proves your competency for both PADI and ADCI credential evaluations. Accuracy, completeness, and professional presentation are not optional—they are the product.

Step 1: Entering and Checking Your Data

Before you calculate anything, transfer all raw field data from your signed data sheets into a spreadsheet exactly as recorded. Do not round at this stage. Create one row per observation and label every column with the variable name and unit (for example, "DO mg/L" or "Temp °C"). Save the original import as a protected sheet so you always have an untouched record.

Once data are entered, visually scan for outliers or obvious entry errors—a dissolved-oxygen reading of 450 mg/L, for instance, is a transcription mistake, not a discovery. Compare questionable values against your calibration logs and logbook notes before deciding whether to flag or exclude them. Any exclusion must be documented and explained in your methods section.

Step 2: Descriptive Statistics

For most aquaculture and marine science field projects, three statistics carry the analysis:

• Mean (average): Sum all values in a data set and divide by the count. The mean tells you the central tendency of a measurement over time or across sites.
• Range: Subtract the minimum value from the maximum value. Range reveals how much a parameter varied, which is often critical for water-quality compliance assessment.
• Percent change: ((Final value − Initial value) / Initial value) × 100. Use this when your objective involves tracking improvement or degradation over time, such as growth rate in a hatchery cohort or change in reef fish density.

Simple trend analysis—drawing a best-fit line on a scatter plot or noting whether values went up, down, or stayed stable across sampling dates—is appropriate when you have at least four or five time points. You are not expected to perform inferential statistics unless your instructor specifically requires it.

Step 3: Producing Publication-Quality Figures

Every figure must earn its place by directly answering one of your project objectives. Two figures are the minimum; more are acceptable if they add meaning. Requirements for every figure:

1. Both axes labeled with the variable name and unit in parentheses.

2. A figure number and a complete caption below the figure that explains what is shown and the key take-away.

3. Consistent font size, clean gridlines, and no unnecessary decorative elements (no 3-D bar charts, no background color fills).

4. Source data identified (your data, your dates, your site).

Submit your draft figure set to your instructor for review before you begin writing. Feedback at this stage prevents you from building your written results section around a figure that misrepresents your data.

Step 4: Writing the Technical Report—Section by Section

Follow the program style guide and work through sections in this order, submitting each as a draft and incorporating instructor comments before moving on:

• Abstract: Written last in practice but placed first. One paragraph (150–200 words) summarizing objective, methods, key results, and main conclusion.
• Introduction: Background context, why the project matters, and a clearly stated objective or research question.
• Methods: Enough detail that another technician could repeat your work. Include site description, equipment used with calibration references, sampling frequency, and any safety protocols observed (PPE worn, dive procedures followed, hazard controls in place).
• Results: Present your data objectively using your figures and statistics. No interpretation here—save that for Discussion.
• Discussion: Interpret your results in light of your objectives. Compare to published water-quality standards or reef health benchmarks from your course references. Acknowledge limitations honestly.
• Conclusions: Brief, direct statements of what you found and what you recommend.
• References: Cite every source used, formatted per the APA or industry citation guide specified by your program.

Step 5: Assembling the Portfolio

Your portfolio is a professional record of the entire project lifecycle. Organize items in this order with a table of contents:

1. Approved project proposal

2. All signed field data sheets

3. Calibration logs for every instrument used

4. Logbook (photocopied or printed pages covering all project dates)

5. Draft figures (both early and final versions)

6. PPE and safety documentation

7. Any dive records (ADCI-format dive logs, if applicable)

8. Final technical report

9. Self-audit checklist, signed and dated

10. Any supplementary material (permits, correspondence, photos)

Conduct your self-audit against the portfolio checklist before submission. Missing even one of the ten required document categories results in a portfolio that does not pass—just as a commercial dive operation cannot legally proceed with incomplete safety records.

Safety Documentation Note

Safety records are not bureaucratic paperwork—they are evidence that hazards were controlled. Your portfolio must include completed PPE sign-off sheets for any confined-space, boat-based, or in-water work. Dive records must show depth, bottom time, gas supply, and the name of your dive supervisor. If lockout/tagout procedures were applied during equipment maintenance at a facility, the completed LOTO log belongs here too. Incomplete safety documentation is a professional and legal liability, and it will prevent portfolio approval.

Scoring and Revision

Your technical report is graded on a 100-point rubric. A score of 75 or higher is required to pass. If you score below 75, you have one week to revise and resubmit. The portfolio is pass/fail: all ten document categories must be present. Build the portfolio incrementally throughout the project so nothing is missing at the end.