Steve Tippins says address validity and limitations early in your dissertation design, not later when templates suggest it. Honest disclosure of limitations helps your committee understand and mitigate them. Treat it as a learning process, not a final product.
In your design chapter or methodology chapter, you want to have a discussion of internal and external validity. You might want to be thinking about it very early, even if the template for your school puts it later. You want to have it thought out and outlined early so that your design is set up in that way. When you do have limitations, honestly say what they are again so that your committee can understand that and perhaps help you design to eliminate or at least reduce some of the limitations. Remember, doing a dissertation is actually the first time you're doing a full research project on your own, so there may be some limitations. This is a learning process, so dive deep into the learning process and learn as much as you can. Drop the word help in the comments and I'll send you a link to my free dissertation help community.
