The Beta scientist outfit is a six-piece costume that is awarded to any member who attended at least four of the eight total Combat beta weekend events.
To be eligible for the set, a player must have logged into a beta world between 4:00PM Friday and 10:00AM Monday (BST/British Summer Time) and participated in that weekend's event. A confirmation message was received in the chatbox if that event counted toward a set piece.
Each of the first eight weekends of the Evolution of Combat beta in 2012 there was a new event for players to attend, and the 4 additional (makeup) events occurred every other weekend running throughout October and ending on the 29th. The official events are usually held by Jagex, but there have been events hosted by other RuneScape players and groups.
Technically none, but high combat skills are advised, in addition to the completion of a number of Morytania quests for easy access.
Complete one or more entire games of the Barrows minigame. Just opening the chest at the end will not count, you MUST loot it. This also means that not a single brother need even be harmed, as the chest may be looted while under attack. Chances of death are high, of course.
Originally, there were only 4 events planned for the outfit, however, since people complained that they were just one event short (most notably being the Pest Control and Barrows events as they required higher combat levels to complete). Due to this, Jagex scheduled more events to make the outfit more obtainable.
The examine info for the various pieces reference common complaints by gamers in multiplayer settings.