C65 · Topic 5.4 · 40 minutes · IOC-1.E
Combining contributions
By the end you can:
- Explain a benefit of distributed participation.
- Identify uneven coverage.
- Distinguish missing reports from absence of a problem.
Before this lesson: topics 1.1, 2.3.
- Crowdsourcing
- Obtaining contributions from many participants to help solve a problem or build a resource.
- Corroboration
- Additional supporting evidence, whose independence and relevance must be assessed.
Understand
Crowdsourcing can combine local observations, expertise or effort from many people, enabling coverage a small central team may struggle to provide. Participation is not automatically representative: who has access, interest, time or incentives affects which contributions appear.
The number of reports does not by itself establish quality or the underlying frequency of events. Duplicate reports may describe one event, and an area with no submissions may lack contributors rather than lack problems. Keep the contribution process visible when interpreting a crowdsourced resource.
Worked example
An invented accessibility map receives 8 centre reports and 2 outskirts reports.
- The observed report distribution is 80%centre and 20%outskirts.
- That does not prove the centre has four times as many actual accessibility problems.
- Recruitment outside the centre could improve coverage, but each report still needs appropriate quality checks.
Explore each concept
Choose a concept, change its inputs and follow the explanation. Each example models the stated rule or scenario; completing it is practice rather than evidence of mastery.
- Distributed human contributions
- Citizen science
- Crowdfunding and scientific collaboration
Change it · step through · explain
Change an input, predict what will happen, then advance one step. Read why the state changes, reset and experiment. This fixed teaching model does not save progress or award XP.
Ready · Make a prediction
- Contributionlocal-observationsWaiting
- Quality checkindependent-reviewWaiting
Ready to explore: Citizen science, shared computation and funding
Why: Change an input, predict the first effect, then advance one step.
Try this: Change one input or choose another listed case. Predict the effect, reset and compare the states and governing rule.
Step through and experiment
Change it · step through · explain
Change an input, predict what will happen, then advance one step. Read why the state changes, reset and experiment. This fixed teaching model does not save progress or award XP.
Ready · Make a prediction
- Input 18Waiting
- Input 22Waiting
- Input 3same-sourceWaiting
Ready to experiment
Why: Predict the first change, then advance one step.
Try this: Keep the counts fixed and change provenance. Then set both counts to zero.
Check a misconception
Claim: No reports from an area proves that area has no obstacles.
It may indicate limited participation, access or awareness rather than an absence of problems.
Guided practice
State a benefit of many residents contributing local observations.
Work with a partner. Make a prediction, compare your reasoning, then identify the rule that supports your answer.
Independent transfer
What extra information could help interpret the 8-to 2 report split?
Exit check
Why should copied submissions not be counted as independent observations?
Write your reasoning before comparing with a classmate. If your teacher assigned this task, submit it through My classes to save your work and receive feedback.
Check yourself
Your practice so far
Check an answer to see its rationale.