The Scrum guide by scrum.org doesn’t mention spikes, but it has something else: the Product Backlog Refinement. And this often gets mistaken for a Scrum Event that puts the entire Development Team in a room with the Product Owner for half a day a week. The entire team then looks at the top of the product backlog and tries to uncover all the details there. They do this until enough uncertainties are uncovered and the team feels confident it can estimate. It gets worse when there is a project manager on board who needs estimations to discuss budgets and delivery dates before deciding whether he wants a story at all. This way, you end up spending a lot of time on value you’re not delivering. At some point, somebody will say: This is taking too long; let’s make it a spike and move on. And that’s not what spikes are for.