In an age where technology advances at a rapid pace, smartphones have become indispensable tools that connect us to the world, facilitate communication, and streamline our daily tasks. As a result, the demand for pre-owned smartphones has surged, offering cost-effective alternatives for consumers and companies. However, when buying a pre-owned smartphone, one must exercise caution, and this is where the importance of objectivity and repeatability in testing and cosmetic grading becomes paramount. 

Objectivity: When assessing the condition of a pre-owned smartphone, objectivity is key. This means evaluating the device's performance, features, and physical condition without bias or undue influence. Objectivity ensures that potential buyers can make informed decisions based on the smartphone's actual state, rather than relying on subjective opinions or misleading descriptions from sellers. 

Repeatability: Repeatability refers to the ability to replicate test results consistently. In the context of pre-owned smartphone testing, this ensures that the evaluation process is not a one-time occurrence and can be duplicated by different individuals or testing facilities. Repeatability helps build trust in the evaluation process and provides confidence to potential buyers. 

To achieve objectivity and repeatability in pre-owned smartphone testing, it's essential to: 

Establish Standard Testing Procedures: Define a set of standardized testing procedures and protocols that can be followed consistently by different testers or organizations. This ensures that the same criteria are used to evaluate all pre-owned smartphones. 

Use Specialized Testing equipment: Utilize specialized equipment, such as testing robots, to ensure that measurements and assessments are consistent across different evaluations. 

Document Findings Thoroughly: Keep detailed records of each smartphone's test results, including measurements, observations, and any deviations from the standard testing procedures. This documentation allows for transparency and verification of the evaluation process. 

In conclusion, when considering the purchase of a pre-owned smartphone, objectivity and repeatability in testing and grading are fundamental. These principles ensure that potential buyers receive accurate, unbiased, and consistent information about the device's condition. By prioritizing these aspects in the evaluation process, end-users can make informed decisions, reduce the risk of purchasing subpar devices, and ultimately enjoy the benefits of a reliable pre-owned smartphone. 

This blog starts a series of test case descriptions that give insights into testing and grading of pre-owned smartphones. In next posts we will focus more deeply on cosmetic grading and most important functional test cases to lighten up why using machines instead of humans and applications brings more benefit and trust.