How can you say that archaeologists are like historians
Archaeologists, those that use material remains to study the past are a type of historian. In the UK, university-based archaeologists are usually a part of the history department and they interpret the archaeological record as a part of history. However, in the United States, archaeologists are found within the anthropology department and the past is viewed through a wider lens, which includes looking at contemporary cultures for clues about the past and understanding how environmental and biological factors shape cultural behaviors.
For American archaeologists, history is still vital to the discipline. No excavation should begin without months of research into the history of the area and the people who lived there. Without the book research, the remains found would lack context. To digress, CONTEXT is one of the most important words in all of archaeology. Without the other objects or histories in which to couch the artifacts found in an excavation, they are meaningless trivialities. Some of those objects might be fascinating, or beautiful in their own right, but without the context they have no further story to tell.
This is how archaeologists are very much like historians. A date, such as June 28, 1914 is important in that was the day that Franz Ferdinand was killed. Historians point to this moment as the spark that ignited WWI. However, that date and that assassination are meaningless without the grander context of the complex network of European alliances that had been in existence for decades before hand. Likewise, to fully see why that date was important one would also have to understand the great advancement in killing technologies and the rapid spread of instant communication or the hundreds of other details that made WWI become the global horror still remembered today.
When archaeologists find a piece of pottery, it tells them that the people in that place and time were using pottery. No surprise in that, it is pretty cut and dry. However, the context of that pottery would tell the researcher so much more. How was the vessel created? What was mixed with the clay? Was it fired or air dried? Was it made of local material or imported material? Are the patterns on it unique to the region or does it show contact with neighboring cultures? Was it a fine material or something for daily use? Was it found in a structure or in a cooking pit? All these questions can only be solved by asking more questions and doing the research. It is almost precisely the same work a traditional historian would undertake, but instead of digging through old archives and attics for lost letters and journals to find new information or rereading old material with a new view, archaeologists must look to the material remains and piece together stories from the objects and the context in which they are found.
Both archaeologists and historians have a love of the past. They want to understand the lives of those people with which they work. Archaeologists are often more prone to working outdoors, they thrive on physical work and miss the field when their life leads them away from excavation. Historians, though not all sedentary, are not generally as physically involved in gathering information.
To sum up the answer to your question, archaeologists and historians both use research to learn about the past. However, where historians are limited to oral histories and the written record, archaeologists are able to physically reach into the past and draw the history from the earth.