Coming from a background in technical writing, it was frequently my task to write text-based instruction. I was usually permitted to complement such instruction with a limited number of figures which assisted the learner in visualizing the instructions being given. There were, however situations where I was limited to text and hyperlink instructions only. This was particularly true for software-based help systems where images were space intensive and difficult to program into the design of the help system.
The use of text-based instructions is not a new methodology and can be beneficial when dealing with new learners, complicated processes, or non-intuitive systems or products. Although it makes it more complicated for the designer to design instructions without the help of images or other visual cues, it is certainly not an impossible task. Similar to designing universal instruction for all learners, you have to describe the visual components to your learners more completely. For example, you cannot just tell them to press a certain button when dealing with new users, you may also have to describe the button and/or the button location. A well designed text-based instruction should be beneficial to learners even without images to support it. The responsibility falls to the instructional designer to “see” the visual components of the instruction for the learner and thoroughly describe them to the learner.
However, a poorly designed text-based instruction may be worse than no instructions at all. I have often received an instruction manual with a piece of software or hardware which was obviously written in another language and translated into English. The original designer had not taken time to ensure the accuracy of the instructions, had not well described the visual components for the learner (me), and then the translation into English was so poor that this further confounded the instructions leaving them to make little or no sense to the learner. In these cases the learner is left to struggle on their own, or attempts to use the instructions becoming hopelessly frustrated and lost. These learners are not helped by these instructions and may be potentially harmed by them.
A good instructional designer will ensure that their instructions are accurate and thorough, regardless of the format by which they are required to present them. This may require having a pilot group with similar characteristics to the intended audience test the instructions and evaluate them to give the designer a chance to make changes prior to implementation of the project.