Even though there are numerous numbers of different theories of love done by psychologists and researchers, Love is a basic human emotion which is not necessarily easy to explain nor understand. Therefore, it is obvious to tell that love is something that science can not explain.
I found interesting theory done by psychologist Zick Rubin who proposed that romantic love is made up of three elements; attachment, caring and intimacy. With his word, "Attachment is the need to receive care, approval, and physical contact with the other person, Caring involves valuing the other persons needs and happiness as much as your own. Intimacy refers to the sharing of thoughts, desires, and feeling with the other person." Based upon his definition, Rubin devised a questionnaire to assess attitude about others and found that these scales of liking and loving provided support for his concept of love.
From personal stands point of view, yes it makes obvious sense to categorize love into three parts. However, I would like to question that would one be strongly positive to tell whether you love someone or not can be determined after go through those questionnaires? Love is so complicate things that one can not define what the definition of love is. It is so ironic that we all seeming to know what love is, but we are not sure how can it really be defined by.