The Personalization Principle is the use of a normal conversational writing voice to convey information rather than a formal writing style. As an instructional designer we almost always used a formal when writing our content.
The common argument against conversational writing as oppose to the formal is that since we know that a computer or video isn’t a person, it shouldn’t be presenting us information in a casual manner. When i worked at university it was policy that all documents issued by the school had to have a certain writing style. This included our e-learning properties. (To clarify I worked for the school, the documents I created were instructions to train faculty and staff in using technology resources) The information delivery view states that is the instructors job to deliver information the best way students absorb it. Student learn better with a conversational voice.

In Mitchell Wolf’s Presentation on applying the principle she includes a quiz on determining the best which is the best usage. The correct writen form of the intro is number 2 as it applies to three of the rules on the checklist as the number 1 applies to none.
—
ref: e-Learning and the Science of Instruction; Ruth Colvin Clark • Richard E. Mayer