Chart assignment

Charts to read and discuss

Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.

  1. How many clinical trials are in each phase?
  2. How much has the US warmed since 1895?

Chart 1 of 2 · Clinical trials

How many clinical trials are in each phase?

The interactive chart needs JavaScript. The numbers are on the chart's page.

52% of the 466,000 clinical trials registered on ClinicalTrials.gov as of November 2026, some 241,000, have no phase: phases describe drug trials, and these test devices, surgery, behavior or diet. Among drug trials, Phase 2 is the most common with about 66,000. Phase 1 tests safety in a few people, Phase 2 asks whether a treatment works and at what dose, Phase 3 compares a treatment with the usual care in many, and Phase 4 follows a drug after approval.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2 (Public domain (U.S. government work); source National Library of Medicine) · Data as of Nov 4, 2026

Open the chart and its numbers

Chart 2 of 2 · Climate

How much has the US warmed since 1895?

The interactive chart needs JavaScript. The numbers are on the chart's page.

The contiguous US averaged 54.6°F in 2025. The warmest year since records began in 1895 was 2024, at 55.5°F. Through 2025, the dashed trend line, the straight line that best fits every year, rose about 0.18°F a decade, or 2.3°F since 1895, and warming had sped up to about 0.5°F a decade since 1970. Alaska and Hawaii aren't included.

How to read this chart

Each point is one year's average temperature across the lower 48 states, in degrees Fahrenheit. The axis doesn't start at zero, so a small rise looks steep: read the numbers on the axis, not the height of the line. The dashed line is the trend, the straight line that best fits every year; single years bounce above and below it.

Questions to discuss

  1. Find the warmest and coolest years on the chart. How many degrees apart are they?
  2. Why might one year be much cooler than the year before, even while the trend line keeps rising?
  3. The axis doesn't start at zero here, but bar charts always do. Why is that fair for temperatures but not for bars?

Source: NOAA National Centers for Environmental Information, Climate at a Glance (Public domain (U.S. government work)) · Data as of Dec 31, 2025

Open the chart and its numbers

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