Data recorded in these ways have never gotten the same degree of emphasis as written materials. But with technical progress in audio-visual techniques and the spread of its use, these have already become too important to ignore.
以這些形式保存的資料一直沒有受到跟書一樣的重視，但隨著視聽技術的進步及應用的普及，已成為不可忽視的資料來源。