These two types of documents have a lot of similarities, but there are many differences as well. It is important to identify those differences in order to decide which assignment you will want to choose.
Instructions are specifically written for an audience to follow, step-by-step, to complete a process. Instructions can be found everywhere: on the back of packages, on single sheets of paper inside boxes of merchandise (bicycles, for instance) or in such infamous booklets as VCR manuals. Good instructions allow the reader to complete the process without difficulty. Poor instructions make the process seem like it’s written in Greek.
Process descriptions, on the other hand, are written to provide the reader with background information on how a process is or was accomplished. The reader is not expected to complete the process and does not have to be an “expert” in the field, but does need details to help understand the complexities of the process. Therefore, process description is often longer and more detailed than a set of instructions.
Since readers are expected to complete the instructions, they should be written in the second person: to the reader. Instructions should be “how-to” steps, placed in chronological order. You need to give your reader the information he or she needs to complete each step, so you need to know your reader’s background, knowledge and understanding of the topic. Remember, you are not writing an essay, so you should use a tabulated format, numbering each step and listing auxiliary information in sub-steps. Your textbook has good examples.
The way you give your instructions is very important. Your reader needs to know that they must perform the steps as you give them. So use the imperative voice (commands). It is much better to say turn off the light then you should turn off the light.
Also, try not to use the verb “take” in your instructions. In other words, “take the butter knife and spread the jelly evenly” is overwritten. You could just as easily say “spread the jelly with the butter knife.” That reduces the step by two words.
Process description uses a more traditional paragraph approach, since you will be giving your reader more background information. The process should still be written in chronological order, but numbered steps are not as necessary. You have to explain more of the whys in a process description. So headings and other technical writing tools will be important for process description.
Process description may be written in the past, present or even future tenses, but it does not use the imperative voice. In fact, process description some times uses that old nemesis we’ve talked about before, passive voice. Think about it: you are looking at a process, not who is performing the process, so passive voice can be used to emphasize the process. Imagine someone talking about how a pipeline was repaired. They probably would say “The pipe was uncovered at 9:20 and removed at 9:35.” The fact that workers uncovered it is not as important as the step itself.
In the next lecture, I will give you two examples looking at the difference between instructions and process description.