Ordinary people are increasingly taking part in scientific research, for example by recording wildlife sightings or measuring air quality with simple devices. I believe the advantages of this development outweigh the disadvantages.
The greatest advantage is the scale of data collected. A university team cannot observe every garden or river, but thousands of volunteers can. In the annual Big Garden Birdwatch in the United Kingdom, hundreds of thousands of participants count the birds they see, giving scientists information about population changes that would otherwise be impossible to gather. Such projects also save money, allowing limited research budgets to be used for analysis instead of fieldwork. In addition, participation educates the public. People who measure pollution in their own street understand the problem better, and this can prompt them to change their behaviour or press local authorities to act. Science also becomes more open and trusted when people feel involved rather than excluded.
On the other hand, there are drawbacks. Volunteers are not trained scientists, and their equipment may be inaccurate, so the quality of the data can be uneven. Mistakes in identifying species or reading instruments can lead to false conclusions, and some participants may record results carelessly or exaggerate sightings. There are also privacy questions when location data from members of the public is collected and stored.
These risks can be reduced. Researchers can give clear instructions, test the instruments, compare volunteers' records with professional ones and use statistical methods to filter out errors. With such checks, the information becomes reliable enough to be useful.
In conclusion, although citizen science raises concerns about accuracy, its ability to gather large amounts of data and to engage people in science makes it a positive development overall.