Interflora Inc & Anor v Marks and Spencer Plc & Anor

When controlling survey-derived evidence before trial, the court should prevent evidence proceeding where it is sufficiently clear that it will be inadmissible, misleading, unhelpful, insufficiently probative or disproportionate. Where the evidence may assist and its significance cannot fairly be determined at an interim stage, permission should generally be granted, leaving weight and further evidential questions to trial.

Witness evidence obtained through a survey may be admissible and probative even where the survey itself lacks statistical validity or cannot be relied upon. Leading questions fall on a spectrum. A question is not automatically fatal because it is leading, but a misleading question may taint the resulting evidence so that it has no value.

Interflora sought permission to rely at trial on witness statements from respondents identified through two pilot surveys. The surveys presented respondents with predetermined search-result pages and asked structured questions concerning any relationship between Interflora and Marks & Spencer.

Interflora did not seek to rely on the pilot surveys as statistically representative surveys. Marks & Spencer argued that the evidence of selected respondents was inadmissible and unprobative without a statistically reliable survey, and challenged particular questions and the proposed witness-selection process.

The central issues were whether survey-derived witness evidence could be admitted without a statistically valid survey, whether the questions materially tainted the evidence, and whether permission should be granted at the interim stage.

1. Permission granted in part. Permission was granted to Interflora to rely on witness evidence obtained through the first pilot survey, but refused in relation to the second pilot survey.
2. The court’s control of survey and witness-collection exercises concerns admissibility, probative value and proportionality. It also prevents costs and court time being wasted on evidence which is clearly incapable of assisting the trial. Because the assessment occurs at a distance from the trial, the court should not exclude evidence where its potential usefulness and significance cannot fairly be determined until fuller evidence and argument are available.
3. The argument that witness evidence obtained through a survey is worthless unless the survey is properly conducted and statistically reliable was rejected. The existing Chancery Division authorities showed that such evidence may be admissible and probative even where the survey itself is not relied upon, lacks statistical validity, or involved flawed questions.
4. Questions lie on a spectrum from open-ended questions, through questions prompting speculation and questions with a leading quality, to completely misleading questions. The first survey’s question concerning a possible relationship between Interflora and Marks & Spencer was leading to some degree, but not so flawed as to taint the resulting evidence. The second survey’s differently phrased question misleadingly implied that a connection existed. Responses to it, and evidence from witnesses obtained through it, were therefore of no value.
5. The proposed selection of respondents who appeared helpful to Interflora went to the weight of the evidence rather than constituting an independent reason to refuse permission. Issues concerning privilege, possible expert evidence and verification of the survey’s conduct could be addressed by agreement or, if necessary, on a later application.