Every removed visit traced to a written rule, applied in a stated order and counted: that is the composite GB892 Unit 2 data preparation record, down to its flow figure. Searches like "gb 892 unit 2 assignment example", "gb892 unit 2 sample" and "gb892 unit 2 example" land here.
What a finished GB892 Unit 2 data preparation record looks like
Six pages: a source statement, an exclusion table, a flow figure, a comparison of excluded and retained visits, and a change log keyed to lines in the cleaning script. The source statement names the extract, eighteen months of inbound gate records from twelve centers, and says the raw file is stored read-only and never edited. The table lists rules in the order applied: drop-trailer visits, outside the study by design, 84,823; duplicate gate-in scans, meaning the same trailer at the same center within ten minutes, 1,817; missing gate-out, 2,896; departures auto-filled at 23:59 during one center's system migration, 1,291; dwell under ten minutes or over twenty-four hours, 716. Each row carries the rule's wording, its script line and its count. The flow figure ends at 196,518 visits.
How a GB892 Unit 2 example is structured
Order is treated as a decision, since the same rules applied in another sequence would assign some records to different reasons and change the counts. The record explains its sequence: scope exclusions first, then errors of capture, then errors of value. Missing gate-outs get the fullest treatment, because they are not scattered at random. Night arrivals lost a gate-out 2.93 percent of the time against 0.80 percent by day, so night visits make up 60.8 percent of the missing group and 29.4 percent of the analytic file. The record states that pattern and leaves its consequences for the limitations section. The migration rule is written narrowly, one center and five named weeks, so it cannot catch a genuine late departure anywhere else. A closing line reports the retained share, 97.6 percent of live visits once duplicates are gone.
Raw file locked, script does the work
No cell in the exported file is ever changed. The cleaning script reads it, applies the rules and writes a separate analytic file, so any reader can rerun the preparation and arrive at the same 196,518 visits.
Scope exclusions are not errors
A drop-trailer visit leaves a trailer and departs without unloading, so its dwell measures something else entirely. The 84,823 removals are labeled as scope, set in the proposal, and kept out of any error rate reported later.
Two scans, one truck
A gate reader that fires twice creates a phantom second visit. The rule, same trailer number at the same center within ten minutes, appears with its threshold and the reason ten minutes was chosen over five.
Who lost a gate-out
A comparison table sets the 2,896 visits missing a gate-out beside the retained file on shift, center group and load type. Night arrivals are overrepresented among the missing by roughly two to one, and the record reports that without softening it.
Five weeks at one center
A system migration at DC-03 stamped every departure at 23:59 for five weeks. Those 1,291 visits, 12.0 percent of that center's post-adoption records, are excluded, which leaves one center-month with no usable visits at all.
Where marks go in GB892 Unit 2
Exclusions described in a sentence, cleaned for errors and outliers, draw the sharpest comment in this unit, because nobody can rebuild the file from that description. GB892 instructors typically compare the count at the top of the table with the count at the bottom and expect every record in between to carry a reason. Rules without thresholds, such as duplicates removed, leave the analyst free to decide case by case. Treating scope exclusions as data errors inflates the apparent error rate and confuses a committee reading it later. Missing data dropped with no comparison of who was dropped hides the night-shift pattern that matters most here. Editing the raw file instead of scripting the change destroys the audit trail. Records reporting the migration problem vaguely, some timestamps affected, leave its reach impossible to judge.
Get a GB892 Unit 2 example written to your instructions
Attach your raw record counts and whatever exclusions you have already made, even informally, along with the Unit 2 prompt and rubric. We return a preparation record with each rule written out, applied in a stated order and compared against what stayed. Turnaround runs 24-48h, and there is no charge for the first custom sample.
GB892 Unit 2 questions, answered
Does a data preparation record count outlier removal as an exclusion?
Yes, and it needs a rule written before any comparison is run. Here the rule is physical plausibility: under ten minutes or over a day cannot be a live unload. Statistical trimming, such as dropping values beyond three standard deviations, is harder to defend with skewed timing data and tends to draw questions about why that threshold was chosen.
How detailed should the comparison of excluded and retained records be?
Detailed enough to show whether the dropped records differ on variables the analysis uses. Shift, site group and load type are the obvious ones in a dock study. A table of counts and percentages is usually sufficient, and formal tests are optional. What matters is stating any imbalance plainly, such as night arrivals missing more gate-outs, and carrying it forward.
Should the record include the cleaning code?
Many sections welcome it as an appendix, and citing script lines in the exclusion table makes the record checkable. The prose still has to stand alone, since a committee member may never open the code. Your program's rules on data sharing and confidentiality apply, particularly where the source organization restricts what leaves its systems.