A useful online lesson helps a learner do something observable: interpret a graph, choose a procedure, explain a concept or complete a task. Start with that result, then choose the text, examples and interactions that make it achievable on the learner's actual device and connection.
Write a goal you can assess
“Understand percentages” is broad. “Given two stated quantities, calculate a percentage and explain the denominator” tells a designer what an assessment should reveal. Record the starting knowledge, the resources learners may use and what a satisfactory answer includes.
Keep the first lesson small enough to review end to end. Ask who is taking it, why the skill matters and where they may get stuck. A short prerequisite check can expose missing knowledge before an elaborate module obscures it. Learners who already meet the prerequisite should be able to move on efficiently.
Choose an assessment before producing media. If the goal is explaining a decision, include an explanation task. Clicking through screens or watching a video can show participation, while the learner's response provides evidence about the stated skill.
Build one complete learning sequence
The following is an illustrative lesson for learners who can divide whole numbers. Its goal is to calculate a response percentage and name the population it describes. The examples are invented, and the sequence is a design proposal rather than a tested intervention.
| Step | Learner experience | What the designer checks |
|---|---|---|
| Orient | Read: 40 people were invited; 30 responded. Which group is the denominator? | The meaning of invited and responded is clear. |
| Show | Work through 30 ÷ 40 × 100 = 75%. Explain why all invitees form the denominator. | Each operation is paired with its purpose. |
| Practice | For 80 invitees and 60 responses, calculate the percentage and explain it. | Answer: 75%; the result describes responses among those invited. |
| Feedback | If the learner divides 80 by 60, ask which count represents the whole invited group. | Feedback addresses the cause of the error. |
| Transfer | A second fictional group has 50 invitees and 35 responses. Compare with the first group. | Answer: 70%, five percentage points below 75%. |
| Revisit | Use a different example after a delay and ask for the reasoning again. | Look for retrieval and explanation, with support as needed. |
The IES guide on organizing instruction and study, released in 2007, recommends spacing study and alternating worked solutions with problems learners solve. Its recommendations carry different evidence ratings. Use it to inform design choices; the guide does not validate every digital implementation or prescribe a universal lesson length.
Provide a worked answer after an attempt, including the reasoning. If several answers could be defensible, supply criteria and examples of acceptable reasoning. Automated “correct/incorrect” messages are insufficient when the goal requires judgment.
Choose media for the explanation
Text works well for a reference, a short argument or steps learners need to revisit. A diagram can show spatial relationships. Video can demonstrate movement or a process that is hard to describe. Use each medium because it clarifies the subject, and remove decorative material that competes with that explanation.
For a narrated demonstration, describe the important visual action as it happens, prepare accurate captions and supply a useful transcript. Include information conveyed visually, such as which control changed or what a chart shows. The W3C media-planning guidance distinguishes captions, descriptions and transcripts and explains how they serve different access needs.
Put instructions beside the activity they govern. Name a downloadable file by its purpose and format. Explain whether the activity saves automatically, requires submission or can be resumed. Learners should be able to tell whether they have finished and where to obtain help.
Review the complete learner path
- Structure: use meaningful headings, descriptive links and clearly labeled controls. A heading should describe the section it introduces.
- Keyboard: work through the lesson without a mouse. Confirm the focus indicator is visible, the order makes sense and every required action is available.
- Text and images: make text readable when enlarged; give informative images appropriate text alternatives; describe information that otherwise depends on color.
- Media: check caption accuracy, playback controls and access to the equivalent explanation.
- Connectivity: provide a low-bandwidth route when possible. Test the actual files and activities; a downloaded reading does not make a hosted quiz available offline.
- Support: provide a named help route and an alternative way to report a blocked task.
Use W3C's development tips as a starting point for implementation. These checks help find common barriers; a full accessibility evaluation needs a broader review and relevant user testing.
Pilot the lesson and revise what fails
Ask a few representative learners to complete the lesson on the devices they normally use. Observe where instructions are misunderstood, which errors recur, how help is requested and whether the final response demonstrates the goal. A small usability pilot identifies problems worth fixing; it cannot establish a general learning effect.
Separate your measures. Completion tells you who reached an endpoint; an assessment examines performance; a later task can probe retention or transfer; a satisfaction question records experience. Keep the original question and scoring criteria available so results remain interpretable.
For the example lesson, an answer of 70 percent with a correct denominator explanation meets the transfer task. An answer of 70 percent produced through an unexplained guess leaves part of the objective unassessed. Add a prompt for reasoning rather than merely adding more screens.
Keep a short revision record: observed problem, proposed change, expected improvement and next check. For example, if learners confuse a draft with a submitted response, revise the submission instructions and verify the confirmation message with the next pilot.