課程：Ask Questions to Make Data-Driven Decisions
Course 2 Module 1: Make data-driver decisions
什麼是Data-driven decision？簡單來說，就是使用「事實」來做決策。使用事實(資料)做決策時，資料的數量及品質決定了其成果。充足並高品質的資料數據可以改善決策，相反資料不齊且帶有偏見時可能就會對決策者造成問題。而使用資料進行決策時，有些陷阱須注意，比如說：過度使用歷史資料、忽略定性資料、蒐集資料時的潛在偏見及分析。
範例：A/B測試，當一間公司開發了新的官方網站後工程師可以將點選連結的客戶分成一半一半，分別導向舊版跟新版的兩個網站。藉由分析兩個網站的銷售成效可以分析出客戶對於新舊版網頁的接受度，藉而提高切換的信心。
Qualitative and quantitative data in business
中文發翻作定性資料與定量資料。定性資料用於描述事物的分類或性質，定量資料用瑜表示數值或數量。我的個人解讀是不可量化與可量化的差異。
Data V.S. Metric
Metric中文譯作指標，基於一或多個量度來評價某個層面的數學函數。
Metric Goal，基於指標所制定的一個可量化的目標。
例如：Lines of Code (LOC)
Tools for visualizing data
如何呈現數據？除了一翻常用的試算表外，目前市面上還有大量的輔助工具。
課程似乎會以Tableau為主軸繼續進行，待後續繼續了解。Tableau的介紹是具有強大視覺呈現輔助的工具，用局於建立圖表、儀表板等拖放式互動介面相當有力，同時也帶有進階數據分析的功能。
常用的儀表板類型
- Strategic: 以最高層級指標所製作的長期目標及策略圖表
- Operational: 短期目標表現追蹤及中期目標
- Analytical: 數據分析所用圖表
接下來討論一下大數據，在處理大數據時要注意以下四個V
- Volume：數據的量
- Variety：數據的種類
- Velocity：數據能夠以多快的速度進行process
- Veracity：數據的品質及可信度
Glossary terms from course 2, module 2
Terms and definitions for Course 2, Module 2
Algorithm: A process or set of rules followed for a specific task
Big data: Large, complex datasets typically involving long periods of time, which enable data analysts to address far-reaching business problems
Dashboard: A tool that monitors live, incoming data
Data-inspired decision-making: The process of exploring different data sources to find out what they have in common
Metric: A single, quantifiable type of data that is used for measurement
Metric goal: A measurable goal set by a company and evaluated using metrics
Pivot chart: A chart created from the fields in a pivot table
Pivot table: A data summarization tool used to sort, reorganize, group, count, total, or average data
Problem types: The various problems that data analysts encounter, including categorizing things, discovering connections, finding patterns, identifying themes, making predictions, and spotting something unusual
Qualitative data: A subjective and explanatory measure of a quality or characteristic
Quantitative data: A specific and objective measure, such as a number, quantity, or range
Report: A static collection of data periodically given to stakeholders
Return on investment (ROI): A formula that uses the metrics of investment and profit to evaluate the success of an investment
Revenue: The total amount of income generated by the sale of goods or services
Small data: Small, specific data points typically involving a short period of time, which are useful for making day-to-day decisions
