Technological knowledge is always in a state of flux - more so than content and pedagogical knowledge. This makes defining and acquiring it notoriously difficult. Keeping up to date with technological developments can easily become overwhelming to time-starved teachers. This also means that any definition of technology knowledge is in danger of becoming outdated by the time this text has been published. There are, however, ways of thinking about and working with technology that can apply to all technological tools, regardless of when they emerged. In that sense, our definition of TK is similar to the notion of Fluency of Information Technology (“FITness”) as proposed by the Committee on Information Technology Literacy of the National Research Council (NRC, 1999). The committee argues that FITness goes beyond traditional notions of computer literacy to require that people understand information technology broadly enough to apply it productively at work and in their everyday lives. FITness therefore requires a deeper, more essential understanding and mastery of technology for information processing, communication, and problem solving than does the traditional definition of computer literacy. Also, this conceptualization of TK does not posit an "end state," but rather assumes TK to be developmental, evolving over a lifetime of generative interactions with multiple technologies.

Technology knowledge is always in a state of flux—more so than the other two “core” knowledge domains in the TPCK framework (content and pedagogical knowledge). This makes defining and acquiring it notoriously difficult. Technology is continually changing, and keeping up-to-date with technological developments can become a full-time job, in and of itself. This also means that any definition of technology knowledge is in danger of becoming outdated by the time this text has been edited, proofread and published. There are, however, certain ways of thinking about and working with technology that can apply to all technological tools. In that sense, our definition of TK is close to that of Fluency of Information Technology (FITness) as proposed by Committee on Information Technology Literacy of the National Research Council (NRC, 1999). They argue that FITness goes beyond traditional notions of computer literacy to require that persons understand information technology broadly enough to apply it productively at work and in their everyday lives. FITness therefore requires a deeper, more essential understanding and mastery of information technology for information processing, communication, and problem solving than does the traditional definition of computer literacy. This conceptualization of TK does not posit an "end state" but rather sees it developmentally--as evolving over a lifetime of generative, open-ended interactions with technology.