There are many options for evaluating your home schooled child's progress. If you are un-schooling, watching their overall development of skills will help you learn which areas they are progressing well in, and which they need more assistance with. It is less important to reach a certain level at a certain time, and the child is more able to enjoy their education. However, it can be difficult to keep track precisely at what stage they are at when using this method. One idea I have heard about is to make a monthly evaluation sheet. You can make it into a game, puzzle, chart, or test, depending on your child's preference. This should give you a rough guide as to their advancement, to ensure they are achieving something of value in the eyes of society for their future, as well as their own happiness and personal goals. You might wish to do this orally, rather than written on paper, or to use a computer. These offer a way of adapting to your child's choices, whilst still finding out at what stage their education is at.
If you wish to evaluate the progress of an elementary aged child using a regular home schooling syllabus, most textbooks will have questions or short tests included. These might be after each lesson, or a single review questionnaire at the end of the book. If you are following an online course, there will also generally be a question section, where you can find out how much your child has actually learned. If this does not really tell you what you wish to know, you could create a self-made evaluation test. Reading through the lessons in the text books, you can make a question about various matters covered. If your child manages to do well in the test, whether oral, written, or typed, then you will know that they are learning well. If not, you will know which areas need revision, before continuing to the next stage in that subject.
Once at the high school level, most children are capable of working partially, or fully, alone. Not being present at all times, you may fail to recognize a problem unless you implement a regular quiz, test, or discussion, based upon the work they are studying. You may still be fully involved, but either way, as they approach the end of their home education, it is a good idea to make sure that all areas are reviewed. Testing your child on their algebra, geometry and statistics, you may fail to observe that their times tables are no longer in their memory, for example. The way I covered this with my son, was to install a yearly exam that covered every topic we had covered during the year behind us. I would set the exams over one week, after marking the results, I would go through the papers with my son, and any time left at the end of the school year would be spent going over any problems or forgotten matters.
Some parents choose to follow an examination syllabus at home, and it is very important to check your child's progress at regular intervals if you choose this option. If they are to sit an exam officially, then any weak points need to be found and dealt with as soon as possible. Luckily, with home education, the parent is on hand to help - providing they are aware of the problem. That is why some form of regular evaluation should be incorporated into the majority of home schooling programs.