Random searching
(1) Conducting an inquiry
On the morning of February 13th in2008, our group conducted a random inquiry in the Antai Bookstore and near the Wuyi Square in Fuzhou. We asked 135 people totally, with 99 valid questionnaires taken back. The people surveyed by us have different educational backgrounds, that is to say they hold different diplomas such as that of primary school, junior high school, technical secondary school, senior high school, junior college, or university.
(3) Analysis of the result
From the bar graph, we find that the people participating in our inquiry know the correct answers to more than 3 questions on average (i.e. they could give correct answers to more than half of the questions).It shows that most ordinary people have a certain rather than a comprehensive knowledge of electromagnetic radiation. Some people even believe that “not all electric appliances produce electromagnetic radiation.” We just surveyed a small number of people ,so errors are inevitable. However, roughly we can conclude that the higher education the person received ,the deeper understanding on electromagnetic radiation he has(except the person who receives a vacational training).From the line chart, we know the fact that most people use mobile phones and computers about 1 to 5 hours per day, while a small group of people more than 10 hours per day. Meanwhile, the chart shows that more than half of them have got some abnormal symptoms after using mobile phones and computers for a long time.