Hard skills are easy to quantify and measure. You can objectively analyze skill level proficiency. In fact, degrees and certificates are often associated with difficult skills such as mathematics, engineering, even some humanities and social sciences. In this field, the principle is measured by the owner, which is regarded as a specific procedure, and a common knowledge base. For Newton, the apple never crashes
Soft skills (roughly simplified) are difficult to quantify and measure and are considered subjective. Several examples include: How do you measure leadership, communication, collaboration? You might say I am going to follow that person, but he / she communicates well and is a team worker. This is a good example of soft skill. These principles vary from culture to culture and may or may not be widely accepted. A part of every research field is the basis of introduction of terms (taxonomy) and information that is theoretically regarded as a fact or common foundation. There are, of course, well-known principles of leadership, but so far it was difficult to find a common ground for evaluating and measuring leaders so far. This may be due in part to the complexity of the personality, the diversity of leadership success, and the complexity of the environment in which they live.
But this is the research field I am studying as I am trying to improve myself. Since there is much information on this topic, let me point out some of the articles / research direction you recently encountered. Other people may answer your question better than I do. Blessing with your search, this is of course a non-exhaustive list
Robles, M. M. (2012). Executive recognition of the top ten soft skills required in today's workplace. Business exchanges Quarterly, 75 (4) 453-465
The main difference between hard skill and soft skill is how to acquire and use them in the workplace. Hard skills are usually obtained through education or specific training. They include the ability to use machines, software, or other tools. Soft skills are seen more frequently as personality traits that you may develop throughout your life. When you manage your time for the first time, communicate with other people, face difficulties, they are summoned. In other words, hard skills can be defined as your technical knowledge, but soft skills are the overall habit in the workplace.
A combination of hard skill and soft skill will form a comprehensive job applicant. Hard skills and soft skills are completely different, but they make a good balance between hard knowledge and interpersonal attributes. Hard skills indicate proficiency and skill, and soft skills indicate communication and human relations skills. Compared to soft skill, applicant's hard skill shows very different, very specific ability. The balance between soft skill and hard skill is important. Hard skills will show the level of experience and qualifications of the job while helping applicants pass the ATS. Soft skills make the applicant humane and prove leadership, empathy, and personality
Hard skills and soft skills - What is different and more important for your professional success than others? My recent articles - Soft skills and 28 Soft skill list? I provided a detailed definition of soft skills. Here I would like to emphasize the three main differences between hard skills and soft skills, and how important they are depending on the occupation you are in. If you are good at hard skills, you usually need clever intelligence or IQ (also known as the left brain, the logical center). To acquire soft skills, you usually need emotional intelligence or emotional intelligence (also called right brain - emotional center). Examples of hard skills include mathematics, physics, accounting, programming, finance, biology, chemistry, statistics and so on. Examples of soft skills include confidence, stress management, and self-management skills such as interpersonal or networking skills. To see a list of 28 soft skills click here.