Emotional Animal

Definition of quality

    Before we can measure quality, we need to understand and define what quality is exactly. Quality is commonly interpreted as something that can be judged but not measured and as indefinable because quality means many different things to many different people. Such a vague understanding of the concept quality obviously could not be helpful to professionals attempting to quantify it. Therefore, the workable definition of quality was created as the conformance of a product to the customers’ requirements.

^Top^

Measurement theory

    Scientific advancement is made through the observation of data resulting in new theories and affirmation or refutation of these theories based upon new data, thus making measurement of that data crucial to scientific progress.

    The first component of a measurement is it scale, the four levels of scales are nominal scale, ordinal scale, interval scale, and ratio scale.

    Nominal scale classifies or categorizes the attribute being measured. An example of this would be the classifications male and female. The nominal scale doesn’t allow for comparisons to be made or mathematical operations to be preformed. So the expression male > female or male < female are invalid. As well, it is impossible to subtract a female from a male. The key requirement of the nominal scale is that each data item can fit into only one category.

    Ordinal scale is vary similar to the nominal scale except categories can be ordered and comparisons can be made. An example of this would be customer satisfaction surveys which often require an answer of completely dissatisfied, somewhat dissatisfied, neutral, somewhat satisfied, or completely satisfied. In such a case, there is a natural order to the scale unlike nominal scales. However like nominal scales mathematical operations still can’t be performed.

    Interval scale indicates exact differences between measurement points unlike the previous two scales. Only the mathematical operations add and subtract can be applied to an interval scale because the zero point on the scale has been arbitrarily decided upon. For example the temperature 20 degrees is hotter than 10 degrees but 20 degrees may not be twice as hot as 10 degrees. The key requirement of the interval scale is that units be clearly defined.

    Ratio scale is the highest level of measurement much the same as interval scales except zero is a non-arbitrary point allowing mathematical operations such as division. Examples of ratio scale measurements are weight and length.

    The next important component is the quality of measurements taken. The two facets of measurement quality are reliability and validity. First reliability, which simply means how repeatable the results are and low reliability indicates that many random errors are occurring during measurement. Second, the concept of validity, which means the metric measures what it intended to measure. Errors in validity, called systematic errors, are usually experienced because not all factors were taken into account when the metric was designed.

    The next component of measurement is causality. The cause and effect relationship has three requirements:

1. cause precedes effect in time or by logic.
2. shown cause and effect relationship
3. direct constant relationship

    When the relationship between variables can be graphed and a line of best fit can be found, however be careful of extreme and inaccurate data values. When defining a casual relationship be sure to watch for the following spurious relationships.

    CASE 1
        Z causes changes in X
        Z causes changes in Y
        X is perceived to causes changes in Y or vice versa and Z is overlooked

    CASE 2
        X causes changes in Z
        Z causes changes in Y
        X is perceived to causes changes in Y and Z is overlooked

^Top^

Many metrics

    Most metrics in software quality assurance fall under one of two categories, product metrics and process metrics.

    Product metrics are for describing characteristics of product such as it’s size, complexity, features, and performance. Several common product metrics are mean time to failure, defect density, customer problem, and customer satisfaction metrics.

• Mean time to failure metric is, to put it plainly, the average time the product runs before experiencing a crash, which is important for systems like air traffic control that are required to have no more than a few seconds of down time in a full year.
• Defect density metric refers to number of imperfections per:
  • Lines of code
  • Function definitions
  • Lines on input screens
• Customer problem metric is a measure of problems customers have encountered with the product over the total usage of the product. This metric takes into account that multiple instances of the product can be used at the same time, which effectively multiplies the length of time the product has been in operation by the number of product licenses.
• Customer satisfaction metric is generally a survey asking customers to rate their satisfaction with the product and/or it’s features on a five-point scale.

Process metrics are strictly for evaluating & improving the effectiveness of development and maintenance processes. Some common process metrics are defect arrival pattern, backlog management index, fix quality, and fix response time metrics.

• Defect arrival pattern metric is a combination of the rate at which defects are reported and the growth of these rates through out the process being measured.
• Backlog management index metric measures the effectiveness of the process by comparing the number of problems that arrive to the number of fixes during a specified period.
• Fix quality metric measures the number of defective fixes compared to the number of successful fixes. A fix is defective when either it doesn’t repair the problem reported or it repairs the problem but introduces new defects into the product.
• Fix response time metric refers to the time between when a problem is reported and the time a fixed is issued.

转自：http://www.womanfriend.com自己看过了，感觉不错

      准备一块 455g 的黑巧克力和1杯235毫升的奶酪 (超市里有整块的出售)。如果不需要一下子做这么多，巧克力和奶酪的分量可按比例减少。巧克力也可以选择自己喜欢的口味，如果你喜欢麦芽夹心，或榛仁的，那么就准备一块夹心巧克力。海报编编偏爱黑巧克力。因为很多营养专家认为，适当食用黑巧克力不仅不会增加体重，更有利于健康。

      将黑巧克力切碎，平均为5毫米的碎屑，当然越碎越好。这可是个苦力活，力气小的MM可得有心理准备！

　　整块都被肢解了，OK！下一步。

 

　　将奶酪倒入锅中融化，锅底要擦干，不能有水哦！

　　奶酪热到可以流动时(再热就要焦了)，倒入巧克力碎屑中。

　　开始搅动，这时候的奶酪温度足以融化巧克力！

       速度要稍快点哦，否则冷凝了，就要返工啦！搅和成没有硬块时，停止。

　　将巧克力汁倒入碗中(留下1/4备用)，等待10分钟。

　　10分钟后，用勺子将碗中的巧克力酱舀出(像舀冰激淋一样，让它们成为球状)。

　　一群可爱的巧克力球！

　　准备3-5勺可可粉

　　留在锅中备用的巧克力汁，此时加热，将巧克力球薄薄滚上一层，再沾裹上可可粉！

       性感诱人的松露巧克力新鲜出炉喽~稍带苦味的可可粉，脆脆的巧克力中层，还有带些余温的酥软巧克力馅儿

      换了新年寄语，2009年的淡然坚持决断总的来说还是做到了，遇事不再慌乱，做事上多了些理性和持续，无论这一年过得怎么样，确实从这三个词汇中受益颇多，一方面是心态，一方面是生活，2010年了，换了新的寄语，依旧是三个词，希望的是这一年能确确实实有一些实际的变化，怎么讲呢，工作在忙碌，生活还是自己的，一直在学习，但总觉得很多事情还差得远，多储备一些总没有错，还有就是要保持的一个动力，09的后半年一直忙忙碌碌的，周末的时间被加班和上课55占用，到还好吧，已经习惯了把上课作为一种放松了，只是希望自己确实能学到一些东西。积累吧，期待有一天能够从质变发生确实的量变。

      前一段的生活总是或多或少的不如意，总有事情纷纷烦烦的打扰着，于是心里闷的要死，很多事情都懒得干，或者尽量往后拖延，本来以为放松一下会好很多，后果却是更多的事情要集中在一起解决。。。于是，在这个月事情是应该有所改善的，坚决施行不妥他政策，每日要完成的必须完成，希望这个月能让感觉慢慢好起来~