A finished DBA-831 Topic 8 pre-specified analysis plan example, fixing outcomes, comparisons, exclusions and subgroups for a plant safety incentive study before any injury data is collected. Searches like "dba 831 topic 8 assignment example", "dba831 topic 8 sample" and "dba-831 topic 8 example" land here.
What a finished DBA-831 Topic 8 pre-specified analysis plan looks like
The finished plan reads as a document written before the study starts and dated to show it. It states the hypothesis, that the incentive program reduces recordable injuries, and the primary outcome, recordable injuries per hours worked over twelve months. Because paying workers for injury-free periods can discourage reporting, the plan names near-miss reports and first-aid visits as secondary outcomes, and it states in advance that falling injuries alongside falling near-miss reports would be read as suppressed reporting, not success. Plants are assigned to start the program in a randomized order. Exclusion rules, the handling of plants that close and the one permitted subgroup analysis are all fixed. Simmons, Nelson and Simonsohn's demonstration of how flexible analytic choices produce false positives is cited as the reason for the plan's rigidity.
How a DBA-831 Topic 8 example is structured
The plan follows the sequence a registry entry would, in seven parts. It opens with the research question, the hypothesis and the date of writing. The second part defines the primary outcome precisely, including its denominator and period, and the two secondary outcomes that guard against suppressed reporting. The third part describes the design: plants randomized to an early or later start, with the plant stated as the unit of analysis. A fourth part fixes the statistical model and the handling of missing months, plant closures and extreme values before any are observed. The fifth states the single subgroup analysis permitted, by shift pattern, and labels any other comparison exploratory. In the sixth part, the plan sets out how each possible combination of results will be interpreted, including the reporting-suppression pattern. The last part explains which deviations would be allowed and how each would be disclosed.
Primary outcome defined to the denominator
Recordable injuries per hours worked over a stated period is fixed as the single primary measure, so no later choice of metric can rescue a weak result.
Secondary outcomes that catch suppression
Near-miss reports and first-aid visits are named in advance because an incentive tied to injury-free time can lower reports without lowering harm.
Randomized start order across plants
Assigning plants to begin early or late by lottery gives a comparison no manager chose, with the plant fixed as the unit of analysis from the start.
Every exclusion rule written first
Missing months, plant closures and extreme values each have a stated treatment, removing decisions that would otherwise be made while looking at results.
Interpretation fixed for each pattern
The plan states what a drop in injuries with a drop in near misses would mean before either is observed, closing the path to a convenient reading.
Where marks go in DBA-831 Topic 8
Plans lose the most ground when they leave the primary outcome open. Naming injuries as the outcome, without a denominator, period or definition, leaves room to choose among several versions once the data arrives, which is the flexibility pre-specification exists to remove. Papers that measure injuries alone miss the reporting-suppression problem the case plants, and so cannot tell a safer plant from a quieter one. Subgroup analyses listed without limit invite the search that finds something by chance. Exclusion rules left for later are decisions that will be made while looking at results. Some plans specify everything except how results will be interpreted, which reopens the door at the last step. Gelman and Loken's point about the many paths an analysis can take is misread when cited as an accusation of fraud rather than a description of ordinary practice.
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Send the DBA-831 Topic 8 instructions and the rubric listed in your classroom, with the study scenario or proposal your section assigned. We write a custom example to them, with the primary outcome defined precisely, secondary outcomes chosen for known distortions, exclusions and subgroups fixed and interpretation set before data, in 24 to 48 hours. The first one is free.
DBA-831 Topic 8 questions, answered
Why commit to an analysis plan before collecting data?
Because once results are visible, decisions about outcomes, exclusions and subgroups tend to drift toward whatever looks significant, often without anyone intending it. Simmons, Nelson and Simonsohn showed how combining a few such decisions can make false findings likely. Fixing them in advance means a positive result was not selected from many possible analyses, which is what gives it evidential weight.
Can a pre-specified plan ever be changed?
Yes, with disclosure. Plants close, data systems fail and definitions turn out to be unworkable. A good plan states in advance which kinds of deviation are acceptable and requires any change to be reported with its reason and timing. What it forbids is quietly revising the analysis after seeing results and presenting the revised version as if it had been planned all along.
What does Gelman and Loken's forking paths idea add?
It extends the concern beyond deliberate fishing. They argued that even a researcher who runs only one analysis may have chosen it in response to the data, and that the other analyses that could have been run still inflate the chance of a false finding. The example uses that argument to explain why the plan fixes choices that seem harmless in isolation.