A table question that asks you to support a conclusion tests whether you can connect the numbers to the exact claim. Read the conclusion first, and list every comparison it needs, including the measures and the time period. Then read the title and column headings; a gain over time is the later value minus the earlier value for the same group. A choice can report true numbers and still fail to show the whole claim.
Hints
- Hint 1
Start with the student's conclusion and identify which changes it compares. Which treatments and measures does it name?
- Hint 2
For the three restored treatments, subtract year 1 from year 3 in both measures. Then compare the gains across the three rows.
Step-by-step
Compare gains across treatments
Step 1Identify the needed comparisons
The student links combining channels and grasses to greater gains over time in both measures. Which comparisons would support that? We need year 1 to year 3 increases in species per plot and nitrate removal, with the combined treatment beating either restoration treatment alone on each.
- Step 2
Subtract within each treatment
How do we measure gains over time in both measures? The column headings pair years 1 and 3 for species per plot and nitrate removal, so subtract year 1 from year 3 within each row. Channels alone gained 1.3 species and 6 percentage points in nitrate removal, with percentage points measuring the difference between two percentages. Grasses alone gained 1.6 species and 7 percentage points. The combined treatment gained 11.1 − 7.8 = 3.3 species and 44 − 30 = 14 percentage points.
- Step 3
Separate true facts from support
Which choices give true facts but miss the comparison? Each restored section increased describes restoration overall, while In year 1 gives starting values without showing gains over time. Native grasses produced slightly larger gains compares grasses with channels without testing the combined treatment.
- Step 4
Check the full comparison
The statement giving 3.3 native plant species per plot and 14 percentage points matches the combined treatment's two increases. It puts those gains above the gains for either restoration treatment alone, so it shows the combined treatment gained more in both measures. Choice D.