What is the legal test for the admission of similar fact evidence?

As was pointed out in R. v. Arp (above), at paragraph 47, courts do not normally engage in weighing evidence when making a determination of admissibility. The determination of weight is generally left for the trier of fact at a later stage of the trial. Given the nature of the test for the admission of similar fact evidence (probative value v. prejudicial effect), however, the court is bound to tread into the area of weighing the quality of the similar fact evidence, at least to some extent, when determining its admissibility. Thus, depending on the nature of the case, the court may at that stage of the proceeding legitimately consider the internal cogency of the proposed similar fact evidence itself. In R. v. Handy (above) the court had to consider whether the possibility of collusion between witnesses so reduced the weight of the proposed similar fact evidence as to render it inadmissible on that score alone. In some circumstances the court may find itself asking the following general types of question when considering the admissibility of similar fact evidence: Is the evidence so murky that its admission would just confuse the issues? Is the witness presenting the evidence so obviously biased (or lacking in credibility for other reasons) that the weight of the evidence is reduced below an tolerable level as a result? APPLICATION OF LAW TO THE EVIDENCE: (a) THE ADMISSIBILITY OF THE SIMILAR FACT EVIDENCE OF D.K.: