Because buyers are often unable to decide what is the best brand of a particular product to buy, and as they are often misled by extravagant advertising claims, the testing of goods is a major function of any consumer service. It is also one of its most difficult problems. Factors which must be taken into account are the extent of consumer interest in a particular product; the need for testing – that is, the extent to which it is difficult for a consumer to make an assessment himself; the cost of testing; and the facilities available for testing. Products in everyday use, particularly those whose merits cannot readily be assessed because of the appeal of different brands, are possibilities for the testing programme. Suggestions are received from district committees and consumer associations and from members who subscribe to the quarterly publication Consumer Service. The testing committee of the Council narrows the number down by eliminating those projects which have special technical or testing problems that cannot be overcome. Articles remaining on the list are documented, where possible, with the criteria for testing. These include New Zealand or applicable overseas standard specifications, as well as appropriate suggestions for testing from suitable authorities, recommendations as to what testing authorities might carry out the work, the number of samples needed, the time allowed, and an estimate of costs. The projects are then referred to the Consumer Council which approves, modifies, or rejects the proposed tests.

When a project has been approved, the Service buys a range of the product, has them tested by qualified and acknowledged experts, and advises which particular brands give the best value for money. It has been shown quite conclusively that in some instances the higher priced goods are not necessarily the highest in quality, and that far better value can sometimes be obtained by buying cheaper brands. Sometimes particular products are found to be unsafe and do not conform to relevant standard specifications. In a test of domestic rotary lawn mowers it was found that they were all unsafe in one way or another. The manufacturers concerned were given in detail the faults of their machines, and the Standards Council was asked to prepare a safety standard. This is an example of the benefit the public derives from the objective investigation of a consumer organisation. The results of these tests, and descriptions of the testing procedures followed, are published in Consumer. Goods so far tested range from babies' napkins to parking meters. On occasion, if testing is not practicable, guides are published which, without assessing the merits of particular brands, give useful buying hints and compare prices, properties, guarantees, and servicing. Sometimes the attention of readers is drawn to false or misleading advertising or packaging, and the more extravagant advertising claims are analysed. General articles are published on subjects such as guarantees, hire-purchase agreements, and rates of interest. Weekly radio broadcasts supplement the information given in Consumer and reach a very wide audience.