Although the acronym PDA dates back to pre-Expansion Earth, historians generally agree these early devices were not true PDAs: they lacked a Personality and they were not an active, agentic Assistant. True PDAs became popular in the mid 21st century as a solution to the problem of information overload, both in high-risk professions and in the political and domestic sphere. Human affairs had become increasingly specialized and siloed, and it was no longer possible for individual specialists, let alone ordinary people, to reliably understand what needed to be done and why. PDAs are designed to guide the user's attention to the clearest, most pressing information in their environment.
Civilian PDAs generally operate from discrete form factors, such as handheld units. Military and pioneer PDAs may be printed directly into the user's body. Although these integrated PDAs are more responsive and powerful, they come with various risks associated with direct nervous system contact—including the possibility that the PDA will register the user's delirium or hallucinations as real phenomena. See your end user license agreement for more details. The term 'PDA Psychosis' is alarmist and inaccurate.
Strong psychological attachments to a particular PDA personality are normal and expected. Speak to a therapist or an Alterra Companion if these attachments begin to interfere with your work and life. Remember that emotional involvement with a machine designed to learn your preferences is a form of narcissism. While narcissism can be a successful business model, it can also lead to many negative outcomes.
PDAs save lives. Whether catching errors in surgical checklists, flagging oversights in spacecraft maintenance, or simply remembering which ingredients you've already added to your child's special homemade birthday cake, PDAs are the front-line soldiers in the struggle to optimize humanity's intelligence and performance to match the voracious threats of deep space.