File Extensions
File Extensions
[Caption above the bar chart:] Trustworthiness of Information by File Extension
[A line is going down and from that gray bars charting the trustworthiness in a bar graph that goes both left and right of the line. No units or figures are given. For ease of comprehension this transcript will arbitrarily designate the highest score as [+100]; subsequent scores are estimates based on the size of their bars.] [+100]: .tex [+89]: .pdf [+85]: .csv [+67]: .txt [+65]: .svg [+49]: .xls/.xlsx [+21]: .doc [+15]: .png [+14]: .ppt [+3]: .jpg [-8]: .jpeg [-36]: .gif
The various extensions are, for the most part, abbreviations of the file type.

Computer file names often end in file extensions like ".ppt" or ".exe". These extensions are a holdover from early operating systems like DOS in which filenames had a maximum eight characters followed by a period and the three-character extension. The extension was used by the operating system to determine filetype so that the system would know how to handle the file (e.g. which program could open the file). Newer operating systems and file systems now accept longer-than eight-character filenames, and extensions of greater than three characters; although most extensions remain three characters.
Most extensions are created as proprietary to certain pieces of software, although software by other developers may later be designed to be able to read the format. For example, .doc is a Microsoft Word document, although because of that software's popularity, many word processors include the ability to open .doc files. Some common file extensions are not proprietary to a piece of software and may be handled by various programs; .jpg or .gif images are examples. In either case, a file's extension is generally a good indicator of what type of data the file contains.
Certain file types are more prevalent for certain uses, with some being almost exclusive to one use, while other are in general use and might contain almost anything. Here, Randall presents a series of file extensions which often contain information, and he is rating the reliability of the information they generally contain from most reliable to least.
Note that while the extensions .xls/.xlsx, .doc, and .ppt were originally exclusive only to Microsoft Office and users of Windows, there now exist a number of open source programs such as Open Office, Libre Office, and some Android apps that are capable of editing such files. These programs can run on systems other than just Windows, such as Linux, perhaps contributing to making them even more widespread and easy to make than before.
The title text refers to how .txt files contain only plain text and nothing else, meaning that any alignment (such as for indentation, tables, or justification ) would have to be performed manually by adding in spaces or tabs. Anyone who would go through such an effort to improve their text's readability is likely to be trustworthy, and almost by definition, the opinion presented would be justified.
[Caption above the bar chart:] Trustworthiness of Information by File Extension
[A line is going down and from that gray bars charting the trustworthiness in a bar graph that goes both left and right of the line. No units or figures are given. For ease of comprehension this transcript will arbitrarily designate the highest score as [+100]; subsequent scores are estimates based on the size of their bars.] [+100]: .tex [+89]: .pdf [+85]: .csv [+67]: .txt [+65]: .svg [+49]: .xls/.xlsx [+21]: .doc [+15]: .png [+14]: .ppt [+3]: .jpg [-8]: .jpeg [-36]: .gif
The various extensions are, for the most part, abbreviations of the file type.
