Up to the year 2008, the universe of the ACTA was representative of the German population age 14 to 64. In the meantime, the universe has been expanded several times. The universe of the ACTA 2015—defined as the "German-speaking population age 14 and over in private households, at main residence in the Federal Republic of Germany"— gives us a total projected base of 69,241 million persons.
Of course, it is still possible to complete time series analyses, which are an important analytical instrument in many areas. In such time series analyses, the base population for the data from the ACTA 2015 should be the "German population age 14 to 64." Such time series analyses enable us to distinguish between long-term trends and short-lived fads, just as they also separate mass markets from products and services that are only of interest to narrowly circumscribed target groups in the medium or long run; they identify the stage in which a particular market cycle finds itself and allow us to make well-founded predictions as to how the population's information and communication behavior is likely to change in the years to come.
The present volume contains the English edition of the "Code Plan by Topics," which lists all of the markets and target groups ascertained in the study. The "Code Plan by Topics" arranges all criteria into 14 different thematic areas and product categories, allowing users to locate individual areas quickly.
The German version of the ACTA report contains several sections that are not included in the English edition: the "Questionnaire Code Plan" (pp. 177-236), which provides the German question wordings, along with information on the media and advertising media contained in the ACTA, and a separate section on "Target Group Models and Market Segmentations" (pp. 237-256), which documents the specific criteria used to define the special target groups which users will find throughout the code plan.