One thing at a time: how make effective assessments

This is specifically from the perspective of math education, but may apply to other areas just as well. Why do we give assessments? Surely the answer is to find out what students know and what students can do. Not in general; we want to know specifically whether students know certain things. We have learning targets…

How compression works and why JPEG artifacts look like that

Do I look like I know what a JPEG is? In a computer, all information is represented as bits, strings of zeros and ones. However, bits can more or less be interpreted as generic numerical data written in base 2 instead of as decimals. In other words, in a computer, all information is represented as…