Good evidence for a claim normally relies on the nature and the context of the claim. The evidence that can support a claim could be different according to various situations. Multiple evidences are required for a good balanced argument.
Examples of good evidences
If there is an expert in a particular field like a historian in history who can provide analysis or a testimony for a particular event, this lends credibility to that particular claim. Even more when this historian is a recognised senior or a celebrity or recognised amongst his peer group. In the similar way, a recognised scientist vouches for an experiment it is considered more reliable especially if the results are from controlled experiments. If the same work is peer reviewed in a famous science journal which has undergone rigorous scrutiny for its data and conclusions made, then it could be considered credible.
We have not observed the German’s gas chambers horrible incident, however there were few who survived this and so gave their version which a number of eyewitness blogs and documentaries that were made later. These were quite strong in relating the history but perhaps with some biasness and perception errors. Apart from these evidences, there are numerous official or well written records and documentation in other areas of interest which are considered as evidence that are acceptable.
Primary Research and methodology as evidences
You can see photos/images taken by few people. This is a good evidence for a claim, however this should be understood with respect to their context where he/she may be having some bias or perhaps could have altered the image using new technology in order to garner some attention. In case of primary research done, data collected acts as a good support for the thesis taken, however this data needs to be relevant, recent for the question undertaken along with good interpretation of these compiled data. Observations made as a part of the research must come from a credible source. Focus groups that have varied discussions both positive and negative needs to be taken into consideration whether the evidence is good or not.
The methodology itself needs to be conducted accurately along with the representative sample size in order to support the claims validity. In case of secondary research, the data sources need to be verified if they are coming from academic published articles or journals which seem to have been reviewed by experts earlier. If you visit a museum or a historical place, all the artifacts that we see and read there, need to be interpreted the way the historians wanted us to understand and possible bias must be excluded here.
Few more examples for good evidences
In case of a business, profits or losses or the cash flow situation for any company is evident through the financial statements and records that are maintained by the company. Market research data, sales figures of the implementation of strategy, customer testimonials and analysis of competitors strategies are good evidences for sales in business. However, those who are not capable of understanding the financial receipts or records or such statistical data, will not interpret it correctly especially as seen in stock market readings.
There are a number of examples to explain that a specific language learning method is the most effective way. If there are various assessments that compare different methods or success stories from different learners, video documentation showing proficiency of various learners all these are good evidences with respect to language. Individuals who are bilingual can show cognitive improvements as well as problem solving skills and standardized tests results are good measure for evidence.
Clinical trials, patient testimonial and various therapeutic approaches which have statistical data are good evidences for behavioural therapy. Added to these, studies on drug’s mechanism of action plus the patient outcomes are important in the biological sciences area. Experimental data are crucial both for physical and chemical sciences. Consistency and reproducibility of these are critical. Economic models and simulations along with various case studies of reduction of unemployment in countries are acceptable evidences for implementing a specific economic policy to reduce unemployment.
In case of Mathematics, in case of a new mathematical theorem, its application and relevance to existing mathematical frameworks along with maths experts’ reviews and acceptance is important. In the similar way, artistic critiques, interviews with various experts in arts fields and any historical documentation and art movements impacts the validity of the claim in arts.
Conclusion
In each area the evidence can be strong depending on its reliability, relevance and context.