Secondary data - Using data collected previously by someone else from sources such as online website and books, Primary Data  - Data collected for the first-time using tools such as interviews and survey's, Bias  - The data source is using unethical and unfair practices of getting data., Size - The sample size must be enough for the data to be valid , Reputation - The sources of data must have good reputation on relevant subjects.,

排行榜

視覺風格

選項

切換範本

恢復自動保存: ?