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The Professor's aides are assistants or scientists that work along side Professors. Aids specialize in many things from office work to field work. Some aids station themselves around areas and report back to their Professor because site studies and information.
In the games
Professor's aides are scattered all over Kanto, keeping tabs on how many Pokémon the player has caught, and gives out rewards, if their have caught a sufficient amount of Pokémon. These aid usually appear on the second floor of lookout stations or in small buildings. The rewards are usually key items, that has a very value. In addition to the the aids, many other aids work in Professor Oak's lab, helping Oak with day-to-day experiments. In total, there are three aids around the region:
There is only one aide helping Professor Elm in the lab, and as a result of this work become very busy for the both of them. The assistant rarely goes out often, and if he did, it would be for a very important reason. When the player enters the lab for the first time, and obtains a Pokémon from Professor Elm, the aide will give the player a Potion when the player heads to leave. He will also give the player five Poké Balls to help the player start on their quest, after the rival steals one of the Pokémon from the lab. After the player reaches Violet City, and defeats Falkner, Professor Elm will send his aide off to the Violet City Pokémon Center, where he will give the player, the Mystery Egg received earlier to the player for safe keeping.
In Pokémon FireRed and LeafGreen, the aides are much similar to the Generation I, where they keep tabs on how many Pokémon the player has caught, and gives out rewards if their have caught a sufficient amount of Pokémon. Most of the items are different to Generation I, including many rarer key items. In Generation III, there is a total of four items, that can be obtained from the aides.
In Generation IV, Professor Rowan's aide will always be the alternate-gender player character from the player. Thus, if the player chose Lucas, Dawn will be the aide, and visa versa. The aide lives in Sandgem Town with their little sister, grandfather, and father - who works as an assistant of Professor Rowan. They are already the Professor's assistant at the beginning of the game. He also demonstrates to the player how to capture Pokémon by capturing a wild Bidoof, before giving the player five Poké Balls to help the player off. On Route 207, the aide will give the player a Pokétch app, the Dowsing Machine, or a key item, the Vs Seeker. Further in the game, the aide will have their Pokédex stolen by a Team Galactic grunt, but gets it back using the help of the player. The aide can be seen at different stages of the game, usually following Professor Rowan around. At the end of the game, the aide, can always be found outside Professor Rowan's lab, in Sandgem Town, usually giving out pieces of advice or help. If the player speaks to either the aide when it is their birthday on the Nintendo DS calendar, they will wish the player happy birthday.